GL1200 Electrical System 101

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Rednaxs60

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This is the follow on to my thread on the "Power Junction – Key Element in the Electrical System". The article on the power junction has blossomed into what is now a 22 page document covering what I think is the entire electrical system.

This thread will revisit some of what I have on my other thread, but is meant to be a consolidated dissertation on the 1200 electrical system. I have revamped some of the information from my other thread to be more current because of the additional research and information I have found.

My research that I have done, and the information used to further my understanding of the 1200 electrical system primarily comes from the automotive industry and a lot of it from the early model vehicle rebuilds. This is reasonable considering the difference in the size of the automobile industry versus the motorcycle industry.

I will use real world experiences to demonstrate that what I mention in this thread works, and as such, could be consider a best practice in going forward.

As always, this thread is primarily to enhance my understanding of the 1200 electrical system, but I do hope that in my presentation of the information, you, the reader will take away an understanding that suits your specific requirement(s).

Thanks for reading. Cheers
 
I have three definitions to put forward before I continue. These definitions are:

Alternator: an assembly consisting of a rotor and stator
Regulator: an electrical component that controls the alternator output. Can be a series or shunt type.
Rectifier: an electrical component that converts AC current to DC current

Now I can proceed with my first post regarding the 1200 electrical system.
 
This is the first section in my article on the 1200 electrical system. It is an updated version of my post on the other thread.

Power Junction - Key Element in the GW Electrical System

There is a power junction buried in the electrical wiring harness. This power junction is the principle electrical junction in the bike's electrical system that makes everything work as it should.
power junction - 2.jpg

Figure 1 - Power Junction

When I removed the old charging system wiring from my bike, I noticed that the two red/white wires from the regulator were joined just inside the wiring harness into a single wire going to the starter solenoid to provide a charge to the battery. I also noticed that this wire was joined to the red wire from the starter solenoid going to the ignition switch as per the above picture. This is the power junction where the power from the alternator goes directly to the bike's electrical system with a power bleed to the battery for battery charging. Unwittingly, I removed this power junction as I did not realize what it was at the time, and wired the system as I thought it should be wired.

This power junction is shown in the various schematics for our bikes and as mentioned, is a key element in system operation.

The power junction separates the electrical into two distinct areas. Downstream of the power junction is the battery and starter solenoid. The battery is for starting the bike, load levelling – voltage spike absorption, and a power supplement. Upstream of the power junction is where the majority of the power is required and it is also the area of the electrical system that controls the output of the alternator as it is where the voltage is sensed by the regulator.

There is almost no voltage requirement at the battery once the bike has been started and the battery has been charged back to a 100% state of charge. There will also be no draw down of the battery state of charge unless the alternator output is less than that required by the electrical system. When this occurs, the battery is used as a power supplement until the alternator discharge is sufficient to power the bike's electrical system without the aid of the battery. The battery will be quickly topped up to a 100% state of charge until it is next needed.
Wiring schematic - 1.jpg

Figure 2 – Basic Main Power System

The power junction is also the location where the regulator sense wire is connected to the electrical system, preferably as close to the power junction as possible. With a 3-wire alternator installation, this sense wire is a separate wire connected to this power junction and routed back to the alternator “S” terminal on the back of the alternator. With the OEM alternator, and one and two wire alternator installations, the sense wire is actually the alternator output wire, and this output wire forms part of the power junction.

The sense wire for a 3-wire alternator should be as close as possible to this power junction to provide accurate voltage feedback to the regulator for alternator output.

The sense wire for the OEM regulator, and the 1 and 2 wire alternator installations form part of this power junction by virtue of the alternator output wire being attached at this power junction; however, the value of the system voltage/current used in the regulator control circuit is less accurate than an alternator with a dedicated sense wire because of where the regulator sampling circuit in the alternator regulator takes the electrical system voltage value from. The sampling circuit in these installations take the electrical system value(s) at the alternator output, not at the power junction. The difference may not be that significant, but it does reduce the efficiency of this type of alternator installation.

I will be explaining how the regulator “senses” the electrical system in another post on regulators; however, suffice it to say that the black wire that is used on the OEM shunt type regulators is not a sense wire but a 12 VDC excitation wire for the regulator and alternator.

The automotive alternator used by many as a substitute for the OEM alternator arrangement, has a series regulator that uses voltage for the regulator comparator circuit to determine what the variable resistance will be in the control element to regulate the alternator voltage output.

The shunt regulator used by the OEM, uses voltage in the regulator comparator circuit to determine what value the variable resistance will be in the control element to regulate the amount of current shunted to ground to control the alternator output to the electrical system.

Once the bike is started, the battery is quickly charged to a 100% state of charge, and once fully charged does not draw a lot of voltage/amperage from the charging system. The battery comes back into play when the charging system cannot keep up with the electrical system power requirements such as at idle, in stop and go situations such as riding in town, or to do electrical system load levelling – voltage spike absorption.

Understanding the power junction and how it is a key element in the operation of the electrical system also gives us insight into how and where we should add additional, new loads to the electrical system.

So how does this affect how we add items/parts to our bikes. The simple answer is that you need to locate the power junction, and quite possibly install new wiring to compensate for the new loads being added to your bike. You have to install additional power loads such that the regulator can compensate for these new loads when being used. Since the voltage/current sensing for the alternator is done at or from the power junction, it would behoove us to add additional loads at, or as close to this junction as possible. Here are two examples of components that can be used as a power junction, or as remote power junctions:
onewire.jpg

Figure 3 – Remote Power Junction
common power bus with cover.jpg

Figure 3A – Blue Sea Power Bus Bar with Cover

Figure 3 and 3A depict aftermarket electrical power connectors that can be used for initial, or add-on power junction(s).

To add additional loads at, or close to the power junction requires us to get into the wiring harness, not the easiest work on a bike, so an alternate location may be required. This alternate location of choice and often recommended is the battery. The battery terminals are easy to get to and the size of these additional loads in amps is generally not that large. Figure 4 shows a battery terminal with multiple connections that was not very well thought out:
Positive terminal.jpg
Figure 4 – Loaded Battery Terminal

It is; however, necessary to limit the connections at the battery terminals to ensure proper operation of the additional loads. The American Boating and Yacht Council (ABYC) that is the default authority for boating electrical systems, recommends a maximum of 4 electrical wire connections at any one terminal as a best practice. In this regard, that would limit the connections at the battery terminals to three additional connections only, and provides a best practice aspect to electrical terminal connections.

Connecting additional loads to the battery terminals is an accepted practice that does work well, but I submit that it may not necessarily the best course of action depending on the size of the load, and whether it is an intermittent, or continuous load. Using the battery terminals for continuous, high amperage load(s) should be well thought out, and in my opinion minimized, as it will be this type of load that could be potentially do damage to the battery.

In my research on this issue, I have found that installing several wires at the positive battery terminal can result in excess corrosion at the terminal, and possibly excess charging of the battery because the current flow at this junction now needs to be more continuous and higher than normal (design intent) to overcome this corrosion and support the additional loads that are connected.

Understanding that the above is a possibility should be a consideration when using the battery terminals as a load connection into the system. For example, adding a heated clothing cord. Heated clothing, liner – not vest and gloves can draw up to 8 amps. Adding additional clothing such as heated chaps, and socks will up the power draw as well. This is a significant current flow to the battery terminal and even thought the intent is for the power to be used by the additional loads, the battery could and probably is, impacted by this current flow resulting in a potential overcharge scenario.

There are some OEM fuse blocks that have additional terminals available so that you can safely add additional loads to the bikes electrical system. If there are terminals available, it would be prudent to install and hook up a second fuse block or power bus to these terminals and power your accessories from here.

Since I had rewired the charging system as I thought it should be, the positive terminal on the battery was always a mess and required cleaning on a regular basis. I could not think of a reason for this, and just kept cleaning the positive terminal on a regular basis, not to mention that I had a few extra wires attached to this post as well. I am of the opinion that the battery may have been subjected to an overcharge condition because of how I wired the new alt mod and having certain additional loads powered directly from the battery terminal(s) such as heated clothing. These changes fortunately were not significant enough to degrade the battery. The battery was load tested and showed no capacity degradation, but the additional connections were enough to cause a corrosive mess at the positive terminal.

I also had the alternator sense wire attached directly to the battery. The alternator still did not work as it should have, but since I have moved the sense wire to the power junction, the alternator performance has improved and is working as one would expect.

I have rewired my alternator mod to suit what I have learned, and find that the system is working much better. The new power junction is where all load connections are. The power to the ignition switch, to the accessory fuse block that I have added, and heated clothing connection to mention a few all come from this power junction.

I now have a correct voltage reading on the dash voltmeter. I have a positive bus bar to add wiring for additional power requirements that will integrate into the electrical system load, and allow the regulator to adjust the alternator output to suit when the additional load(s) are applied and removed. I will also be able to “daisy” chain more positive bus bars if required, and have the new loads integrated into the electrical system. The wire harness to plug in the battery tender is also connected to the new power junction because I do use it for other reasons such as providing power to my heated clothing when out and about.

Having refreshed the section on the power junction, I believe that the discussion on the bike's electrical system should be expanded to incorporate all the components of the electrical system. I will try to discuss each component in its own section, but expect some duplication as I go through this article.
 
Next installment is about batteries. We take batteries for granted, and generally abuse batteries. I believe this to be primarily because batteries for our bikes or even our vehicles are relatively inexpensive. I lived on a 40 foot boat where the battery replacement cost was upwards of $3,000.00 for the Lifeline AGM 8D batteries. On to the subject at hand.

Batteries

Batteries are generally the first item that gets renewed when a person purchases an older GW, or replaced due to age. We all expect/hope that the components in the electrical system will work well beyond the life expectancy of the battery.

Batteries have a calendar life, shelf life and cycle life.

Calendar life is that where the elapsed time before a battery becomes unusable whether it is in active or inactive use. Key factors that influence calendar life are temperature and time.

Shelf life is similar to calendar life in that it is the time a battery can be stored before use. Shelf life is generally said to expire when an inactive battery has been stored and has reached a state of charge of 80 percent.

Cycle life depends on the type of battery. This is defined as the number of complete charge - discharge cycles a battery can perform before the battery state of charge that can be maintained falls below 80 percent of the initial rated state of charge.

There is a considerable amount of information regarding the life expectancy of batteries and how each element affects a battery that you may be considering buying. I mentioning the above three life aspects of batteries so that you will consider asking a few questions regarding your battery purchase such as date of manufacture, how has the battery been stored, and such.

Batteries that are available for our bikes are of the lead acid type; flooded cell, AGM, and Gel. The newest battery on the market is a lithium battery. There are pros and cons for each, and availability of the older technology such as a flooded cell lead acid battery for a motorcycle may be difficult to source if one were inclined to use this type. The newer batteries are a considerable improvement over the lead acid battery, but each has benefits and some draw backs as well.

The state of charge for all lead acid batteries is generally the same. It may vary depending on the state of charge, or the type of lead acid battery; however, these lead acid batteries all discharge at approximately the same rate depending on age of the battery, and temperature.

A standard state of charge chart is:
battery-condition.jpg
Figure 1 – Battery State of Charge Chart

Motorcycle batteries are storage batteries, store electrical power which is generated by the bike's charging system, which in turn is powered by the engine.

Batteries designed and installed on our bikes are designed to provide power for the starter, load levelling - voltage spike absorption, and supplemental power when the charging system is not producing sufficient output to the electrical system. This is the accepted use of a battery in a vehicle electrical system. The wiring to provide a charge to the battery is sufficient for this task, but may not be adequately sized for additional loads to draw power from. It is also sized for short duration charging of a 100% state of charge battery.

It is generally accepted that a battery in good condition will probably be discharged approximately 3% of the battery charge at time of use. This discharge percentage will invariably change depending on the state of charge at time of use. I would submit that the amount of discharge will increase, probably exponentially, as the state of charge is less at time of starting the bike. This 3% discharge is easily and readily topped up by the charging system soon after the bike is started.

Another accepted norm for this type of battery is that it can withstand approximately 10 deep cycle discharges before it needs to be replaced. I think this is based on a car battery, and that because the size of a motorcycle battery is considerably smaller, a motorcycle battery may not meet a 10 deep cycle discharge parameter.

From my research, I have found that it is never a good idea to re-charge a low battery, or dead battery as we know it with the alternator. The high current and voltage requirements can be hard on the charging system components, and electrical system wiring and components. A battery that has been drained, can require a significant amount of power to come up to a 100% state of charge, and in doing so the voltage in the electrical system can be greater than the requisite design voltage of approximately 14.2 VDC. This could result in electrical system components being damaged as well and cause premature battery failure. A battery that has been drained sufficiently to require a boost, or is at a low state of charge should be charged by an industrial, workshop type charger. The alternator purpose is to operate the vehicle electrical system, provide the battery with a quick charge after staring the bike, and keep the battery topped up for future use.

Lead Acid Battery

The lead acid batteries, flooded, absorbent glass mat (AGM), and Gel all do the same job. The flooded lead acid battery is a mainstay in several applications, but have been surpassed in the motorcycle industry by the AGM and Gel batteries. A newcomer to the motorcycle market is the lithium battery.

Flooded, wet cell lead acid batteries contain liquid electrolyte and are lowest in initial cost. They’re usually not sealed, so the water in the electrolyte that’s lost while charging the battery can be replenished. Failure to replace the water can damage, or ruin the battery and is one of the most common reasons wet-cell batteries fail. Wet cell batteries are the most fragile type, and the acid can do extensive damage if it leaks out.

Wet cell batteries require regular, periodic checks of electrolyte levels. In hot weather and following extended high-speed use, they may need to be topped off every few days or weeks. With the battery positioned level, the height of the electrolyte must at least cover the top of the plates inside, and should be maintained at or near the full marks. Distilled water should be used to replace the water than has been lost. It's not a good idea to use regular tap water because it contaminates the battery with unwanted minerals, shortening its service life. When removing caps, be careful not to splash the acid-bearing electrolyte, which can destroy clothing, paint and cause severe burns, and even blindness if it gets in the eyes.

Protective gear is highly recommended when working with wet cell batteries such as wearing rubber gloves and eye protection. Wet cells can be checked for charge level with a hydrometer. A 100-percent charge yields 1.265 specific gravity, 1.225 is 75-percent charge, 1.190 is 50-percent, 1.155 is 25-percent and 1.120 is discharged.

Wet cell batteries are the most maintenance intensive of all the batteries available for use in motorcycles. These batteries can also be the most problematic because they are not sealed units.

Gel cell batteries are sealed units, and use thick electrolyte fluid so they do not spill if they tip over. The Gel cell battery is a valve-regulated lead-acid battery (VRLA battery) sometimes called sealed lead-acid (SLA – AGM batteries are classified as such as well), Gel cell, or maintenance free battery. The sulphuric acid is mixed with fumed silica to make a gel like mass that allows the installation of this battery in various orientations, not necessarily upright. This gel like mass reduces electrolyte evaporation, spillage, and has greater resistance to to shock and vibration.

Both the wet and Gel cell batteries have lead plates inside but the thicker gel holds up to the rigours of riding quite a bit better and the special vents only allow gas to escape if it is overcharged so there's almost no risk of getting any fluid on you or your bike. The introduction of the Gel battery was the next step in the evolution of power sport battery technology but it has quickly been surpassed by the AGM type. Gel batteries generally require lower charging voltage, so you will need to adjust the charging equipment accordingly. Check the rating on the side of your specific battery, before you hook it up to the charger.
AGM, also a VRLA battery, uses a fibreglass-type glass mat separator to hold the electrolyte in place. AGMs are spill-proof and the most vibration-resistant lead batteries available. AGMs typically last longer than wet or gel cell batteries, offsetting their extra cost. AGMs batteries use almost the same voltage set-points as wet cells and thus can be used as drop-in replacements for them. Both Gel and AGM batteries can deliver power at about a 25-percent higher rate than flooded cells. However, since they are also sealed and are valve-regulated lead acid battery, charging has to be controlled or they too can be damaged.

Gel and AGM batteries require no maintenance as long as the charging system is properly set up, and an appropriate battery charger for a VRLA battery is used. They have no electrolyte to replenish, and never require specific gravity checks.

Advantages of AGM and Gel VRLA batteries:

1. Have shorter recharge times than flooded lead acid batteries;
2. Discharge significantly less hydrogen gas;
3. Safer for the environment; and
4. Can be used or positioned in any orientation.

Disadvantages of AGM and Gel VRLA batteries:

1. Cannot tolerate overcharging, overcharging of these batteries results in premature failure; and
2. Have shorter, useful life than properly maintained wet cell batteries.

The one aspect of all lead acid batteries is thee requirement for long charge times that should consist of a bulk and float charge. Lead acid batteries will accept a bulk charge up to 70% rather quickly, and require a float charge for the remaining 30% for an extended period of time, up to 10 hours depending. To ensure longevity of a lead acid battery, it should be kept at full charge when stored, and when being used depth of discharge should not exceed 20%. These are accepted norms and provided as information. If you, the reader require additional information, there is a plethora of information awaiting for your perusal be it the internet or like sources.

Lithium Battery

Lithium batteries are the latest newcomer to be used in motorcycles. Lithium batteries are not to be confused with a lithium ion battery.

Lithium batteries, sometimes called lithium-metal batteries, have a high charge density (long life) and high cost per unit. Charge density is basically the amount of electric charge per unit length, surface area, or volume. There are other variables, but these are the primary ones.

There are many reasons for an upgrade to the lithium battery, but an understanding of the limitations and what you as a user of this type of battery should know is paramount in enjoying the benefits of a lithium battery. For myself, I will continue to use an AGM battery as there are other aspects of riding and maintaining my bike that require my attention, more so than the battery.

Advantages of lithium batteries:

1. Lithium batteries have a higher energy density, so they can have a higher output at a lighter weight. They are usually about a third of the weight of the standard lead acid battery supplied as original equipment in almost every motorcycle;
2. These batteries have a longer shelf life when not in use. Many batteries we buy have already been sitting on the shelf for some time so we are only getting a portion of their maximum capacity;
3. Motorcycle batteries are constantly being recharged, which reduces their life. Lithium batteries are able to be recharged a far larger number of times. So they cost more than a lead acid battery, but will last much longer;
4. If it does run flat, it can be recharged very quickly, but needs a special charger or a simple charger without desulphation modes;
5. Lithium batteries have a lower internal self discharge rate to lead acid batteries so they do not need to be tendered in winter or periods of disuse in the manner lead acid batteries do. Typically, a lithium battery can be left unused for up to six months without charging, whereas a lead acid battery would need the battery charged far sooner;
6. A lithium battery may start your bike quicker because lithium is a lower impedance internally which allows delivery of up to 90% of the stored energy in one hit. Lead acid batteries typically can only deliver around 1/3 of the stored energy in one go. Hence the Lithium batteries have higher CCA ratings (Cold Cranking Amps);
7. If you are customizing your bike and want to create a void where the battery usually lives, use a lithium battery. They are much smaller and can be located anywhere and at any angle; and
8. You should purchase the largest-capacity Lithium battery you can.

Lithium Battery Disadvantages

1. Be careful not to overcharge lithium batteries as they can overheat. Make sure you charge them with a suitable, lithium battery charger; and
2. Lithium batteries are susceptible to extremes of cold or heat. Understanding how cold and heat affect a lithium battery is required but discussion items for another topic.

I have included a short mention on the varying battery types available as a preamble into the world of batteries and the rest of this section. The above information has been gleaned off the internet web sites and it is recommended to do additional research to ensure you get the right battery for your application. Most of the following information that I have come to understand is primarily related to lead acid batteries and not the newest technology available, that of the lithium battery.
 
This installment is about the charging system itself and is a precursor to the various components that make up the charging system, specifically the alternator and regulator.

Charging System

The electrical system is regulated to a mean voltage of 14.2 VDC. The 14.2 VDC level causes about the correct amount of current flow through the battery to maintain a battery in a fully charged condition once the battery is at 100% state of charge. Extended periods with higher than 14.2 VDC level could over-charge the battery at most temperatures.

Hooking additional loads into the system will generate as many recommendations as questions asked, if not more. There is really only one convenient place to do this and that is at the battery. There are aftermarket products that can be purchased to simplify the installation and are quite elegant when installed, but the battery terminals as the connection point into the electrical system for additional loads may not be a best practice even though this has been the accepted practice for years. What is required is an understanding of the operation of the bike's electrical system, and how we affect this system with what we do.

Connecting additional loads at the battery terminals does integrate these new loads into the electrical system load. These new loads are powered by the alternator when the bike is started, not the battery. This is because the alternator output is at 14.2 VDC and the battery voltage is at approximately 12.7 VDC. Voltage is the electrical system pressure and you cannot force 12.7 VDC into a 14.2 VDC system. The battery does power these loads if used with the bike is not started.

When you do connect loads to the battery, using a relay to ensure the loads are off when the bike is not started is a prudent consideration. Not doing so will require you to ensure the loads are turned off; however, we have all left loads on that drain the battery at the most inappropriate time.

I think we can all agree that the charging system is at 14.2 VDC and the battery is at 12.7 VDC. Because of this, all loads are now being provided operating power from the charging system through the bike's electrical system, even the loads attached to the battery terminal(s). I mention this because voltage, electrical pressure, works the same as any other fluid system we know. You cannot force 12.7 VDC into a 14.2 VDC system, just is not going to happen. That is until the electrical system voltage drops below that of battery voltage, then the battery will supplement the electrical system power requirements.

When the battery is fully charged to a 100% state of charge after the bike has started, the battery is in essence a “passenger” until it is required to supplement the electrical system power requirements, or start the bike again.

The wiring to the battery as designed has no additional loads connected, has very little voltage/current flow going through once the battery has been brought to a 100% state of charge; however, when we attach loads to the battery terminal(s), there is increased voltage/current flow through the wires to the battery. I surmise that there is a possibility that this additional voltage being supplied through the wiring to the battery, not as per the design intent when built in my opinion, could have an adverse affect on the battery even though the power is meant to be used by the external loads connected to the battery terminal(s).

I found an article on the internet that mentions that the additional current flow to the battery terminal could potentially be detrimental to the battery and result in having the battery in an overcharged condition. This is because there is no control over where the additional current will flow at all times.

Charging System

The charging system has evolved considerably from the '60s when I started driving in the '60s. Generator(s) with the external black box regulator, vacuum wiper blades – never did work well, 3 on the tree standard shifts, very few electrical accessories, lights dimming, always having issues in the winter starting, being able to remove a battery with the car running and putting in a replacement (can't do that today) and such.

The charging system design intent to charge the battery was at the forefront of the electrical system back then. Today, the charging system is in my opinion a system to power the vehicle with battery charging as a secondary roll. Vehicles start so much easier today, and require a smaller battery to do this. If the design intent is met, the battery is depleted approximately 3%, but topped up quickly.

Conversely, the additional power requirements to support the plethora of electrical loads has increased significantly. Power seats, heated seats and hand grips (steering wheel), car seat cooling, navigation systems, just about every vehicle is fuel injected – can't think offhand if there are new cars with a carburetor, on our bikes – auto air ride suspension. Our bikes are equipped with Navigation systems, heated seats/hand grips, USB and other 12 VDC connections. A lot of bikes do not have these as a factory install, but the owners want to have the same functionality. In this regard there is a lot of discussion on the various forums regarding alternator amp sizing, not much on a larger size battery.

Another thought is having more than one battery on our bikes, even read of people installing car batteries. This is an interesting idea. It can provide additional power when at a camp site, when the bike is not operating, the second battery could be a deep cycle battery and be isolated from the starting battery so that you would always be able to start your bike and move on.

The only caveat I have regarding this is the charging capacity of the GW with an OEM alternator. Adding a second battery to the electrical system is a modification that would be well served by the owner doing a load survey of their bike. Discharging the second battery, and using the bike's electrical system to charge after use needs to be well understood, wired and executed, especially if you are using the older internal OEM alternator in these older GWs.

I have had experience with this having lived on a 40 foot boat for 5 years, and previous to that owning a 30 foot boat that was used every weekend during the boating season with solar panels to supplement the battery charge when we were at anchor, and to fully charge the batteries during the week when we were at work. I also had sufficiently large enough alternators to compensate for the additional charging requirements.
 
This installment is about the regulators used in our bikes.

There are 2 types of regulators regularly used in charging systems. Both are linear type regulators, one is shunt type and the other a series type as per this attached picture. The series regulator, this one from Roadcraft is on the left and the OEM shunt type regulator is on the right. I had both installed on my 1200 before the stator failed and I installed the external alternator modification:
SH847 and Shindengen.jpg
Figure 1 - Series and Shunt Type Regulators
The series regulator from Roadcraft is a five wire regulator; 3 wires in from the alternator (infamous yellow wires) and a ground and alternator output wire. The shunt style OEM regulator has 8 wires; 2 ground wires, 2 alternator output wires, 3 alternator wires (infamous yellow wires) and a switched 12 VDC excitation wire.

Both types of regulators have the same control elements: sampling and comparator circuits, reference voltage and control element with the main difference being whether the control element is in parallel or in series with the electrical system load.

The series regulator is one where the regulator control element is in series with the unregulated DC current input to the regulator by the alternator.

The other type, a shunt regulator has the regulator control element in parallel with the unregulated alternator output and the control element shunts some of the unregulated DC current to ground.

External alternator regulators are classified as series regulators, as is the series regulator above, with the control element in series with the alternator output. The control element either restricts, or allows power to flow from the alternator into the electrical system:
Voltage-regulator.jpg
Figure 2 - Series Regulator Schematic

Shunt type regulators like the OEM regulators on our older GWs have the control element in parallel with the alternator output and shunt load current to ground to regulate the alternator output:
Shunt-regulator.jpg
Figure 3 - Shunt Regulator Schematic

The control circuit in both types of regulators work the same.

The sampling circuit takes a voltage sample that is compared to the regulator reference voltage in the comparator circuit. The resultant value from this comparison, plus or minus from the reference voltage, changes the resistance of the adjustable resistance element in the control element.

If the resistance in the control element increases, the shunt type regulator reduces the DC current being shunted to ground increasing the alternator output to the electrical system. Conversely, if the resistance in the control element reduces, more current will be shunted to ground reducing the alternator output. There is always some DC current flowing to ground.

The same happens for the series type regulator with one main difference, DC current is either blocked or allowed to flow out of the regulator.

The rectifier in the shunt and series regulators, converts an unregulated AC current from the alternator to an unregulated DC current prior to the regulator. This AC/DC current is an unregulated current because regulation of this current is done by the regulator component of the alternator assembly not the rectifier.
 
This installment is to discuss the bike's alternator whether it be the OEM alternator install or an external alternator install.

The alternator is the heart of our vehicle's electrical system. On our older bikes we have an internal alternator, connected to an external regulator/rectifier.

The charging system on my '85 LTD fuel injected model has an internal to the engine 500 watt alternator, whereas the carbureted 1200 models have an internal to the engine alternator of 350 watts. The alternator provides continuous unregulated AC power that is converted into an unregulated DC current by the rectifier to the regulator for output to the electrical system as required. The amount of unregulated AC current from the alternator is dependent on the speed at which the alternator is spinning.

The regulator is designed to deliver a mean voltage of 14.2 VDC to the electrical system. How this is done is detailed in post #6 above.

This type of OEM charging system, internal alternator with an external regulator/rectifier allows for space savings, but appears to have a limiting size because of the internal alternator and still maintain a reasonable reliability level.

Before I get to the external alternator modification, lets look at the OEM alternator with an external regulator/rectifier.

The rectifier works the same regardless of the regulator it is attached to, converts unregulated AC current to unregulated DC current.

The OEM alternator consists of a rotor and stationary stator internal to the engine. The stator can be removed when it fails and in most instances this requires the engine to be removed.

The regulator as installed by the OEM is a current shunt regulator that provides power to the bike immediately on start up. It achieves this by having a 12 VDC switched input to the regulator that provides power to turn on the regulator and put full field current to the alternator immediately at start up. If there was not a switched 12 VDC power supply to the regulator to turn the regulator on and provide electrical power to develop full field current, the alternator output would be a gradual build up until the alternator developed full field current. This excitation wire is not a sense wire.

This being a current shunt regulator, the regulator senses electrical system voltage through the alternator output wire in the sampling circuit, compares this voltage in the comparator circuit against a reference voltage and adjusts the variable resistance in the control element shunting current to ground if required reducing alternator output, or reducing the amount of current being shunted to ground increasing alternator output. In doing this the alternator output is adjusted to compensate for the increased or decreased load requirements. In this type of regulator, current is always being shunted to ground, and the control element is in parallel with the load.

From the internet:

“A shunt voltage regulator works by providing a path from the supply voltage to ground through a variable resistance. The current through the shunt regulator is diverted away from the load and flows uselessly to the ground, making this form usually less efficient than the series regulator. It is; however, simpler, sometimes consisting of just a voltage-reference diode, and is used in very low-powered circuits wherein the wasted current is too small to be of concern. This form is very common for voltage reference circuits. A shunt regulator can usually only sink (absorb) current.”

External Alternator Modification

The GW fraternity that operate these older vintage GWs have come up with various modifications necessary to keep these venerable old girls operating. One of these is the “Poorboy” external alternator modification that mounts an external automotive alternator on the front of the GW. This modification is a good alternative to the OEM alternator system, but is not for everyone.

This alternator is driven by adding a pulley to the crankshaft and using a belt, V or V-grove, up to the alternator. There are some chassis modifications required as well, but nothing a good DIY handyman cannot accomplish. There is a Poorboy alternator install kit complete with the electrical and chassis components necessary for install.

The alternators available are plentiful and vary in amperage ratings. The modern automotive alternator is probably more effective and efficient than the OEM alternator assembly with its external shunt type regulator, and as such, an alternator in the same amperage range as the alternator installed by the OEM at the factory will probably be more than adequate for whatever additional power requirements you can envision.

There is also the size of the alternator and the space available for installation. There is very limited space on the 1200 carbureted models and even less on the 1200 fuel injected models (primarily because of the additional fuel injection (FI) components such as the throttle position sensor). With this in mind, a maximum amperage of approximately 55 amps is reasonable in physical size and amperage rating for a 1200 fuel injected bike, whereas a 35 or 40 amp alternator will be a good candidate for a carbureted 1200 GW.

Another issue with this modification is knowing what vehicle the alternator is from. From personal experience, this is a key issue should you be away from home touring and have an alternator failure. Not knowing the vehicle make, model and year can cause significant frustration, and loss of time, even cancellation of the trip with the added expense of getting your bike home.

I will also mention that when on the road away from home, with the external alternator modification installed, it is much easier to replace an external alternator than it is to have a internal alternator stator replaced.

These automotive alternators generally have an internal voltage regulator, but if you are so inclined you can use an alternator that requires an external regulator, or have an alternator modified to use an external regulator. Depends totally on your sense of adventure.

There are three types of automotive alternators available for use. One-wire, two-wire, and three-wire. Each has its merits and expertise requirements.

One-Wire Alternator

The one-wire alternator, also known as a self-exciting alternator, is the easiest alternator to install as there is only one wire from the alternator to the connection in the bike's electrical system. This alternator output wire should be hooked up at the power junction. The two wire alternator will be hooked in to the power junction in a similar manner.

The one wire alternator turns on the internal voltage regulator when the engine starts turning the alternator. This happens because there is residual magnetism in the alternator from past operation. It is also assisted by the minute electrical current that is fed back through the rectifier assembly. The rectifier diode assembly is a one way switch; however, there is an extremely small feedback into the stator winding that in essence keeps this residual magnetism alive for the next time the alternator is used. The output voltage is not instantaneous on startup as with the 3-wire alternator, or the OEM installed external regulator because there is no external 12 VDC excitation applied to the alternator

The one wire alternator will eventually lose all residual magnetism such as from sitting on a shelf for a long time, or from not being used such as when we put our bikes away for the off season. These alternators can be resurrected by exciting the alternator from the bike's 12 volt system. How this is done is dependent on the alternator. You may want to remove the alternator, take it to an electrical shop and have it done for you. There are good YouTube videos regarding this as well.

Two-Wire Alternator

The two-wire alternator is a cross between a one and three wire alternator. It is also easy to install as there are only two wires to contend with, one for the alternator output, and the other is a switched 12 VDC excitation wire. This switched 12 VDC wire is connected so that the alternator starts charging as soon as the engine is started. The difference between this alternator and a 3-wire alternator is that there is no dedicated sense wire. The 2-wire alternator senses system voltage through the alternator output wire.

Three-Wire Alternators

Three wire alternators from my research and personal experience are the best choice for the alternator modification.
3-wire connections - 2.jpg

Figure 1 – 3 Wire Alternator Connections

This alternator has an output to the electrical system, a dedicated sense wire – generally identified as terminal “S”, a 12 VDC wire switched connection – terminal “IG”, and a dash lamp light indicator connection – terminal “L”. The alternator output is terminal “B”. This alternator also requires a better understanding of the electrical system so that it is installed correctly, and the output and sense wires are in the correct location in the electrical system power distribution wiring.

The dedicated sense wire for a 3-wire alternator setup is normally referenced as a remote voltage-sensing wire. This is an excerpt from a web site:

“The alternator is the source of power used to operate the ignition system, lighting, and other electrical system parts. And the parts will deliver best performance when operating at about 14 volts. The voltage regulator will always attempt to maintain the electrical system voltage at about 14 volts. But the original wire harness will feed power to these parts from a “main junction” in the wiring, which is often far downstream from the alternator. The voltage regulator can maintain 14 volts at the “remote main junction,” if we give the regulator opportunity to read “voltage-sensing” from the junction.”

The one wire alternator, without the remote voltage-sensing option, as an “intended up-grade” can result in dim lights, weak ignition, and weak performance in general because the one-wire alternator sensing mechanism is the output wire and the voltage being referenced can be different from that of the electrical system. The further the main junction, or power junction as I have come to know it, is downstream of the alternator, the less reliable the voltage reading for electrical system adjustment can be. We all know that voltage at the source (pressure) will always be greater than the voltage (pressure) downstream, and a resulting drop of even .5 VDC or more, can affect system performance. This can be the case when an alternator upgrade has been done using a one or two wire alternator with the “factory-original” type wire harness system is used, and is directly related to where the alternator voltage sensing location is.

The benefits of the 3-wire alternator adapts to the electrical system requirements in a more timely manner with more accurate electrical system voltage information than the one and two wire alternators, even the OEM installed charging system.

The 3-wire alternator relies on the sense wire voltage input from the power junction to increase/decrease the alternator voltage. This is different from a one or two wire alternator installation in that the voltage feed back to the one or two wire alternator installation is through the alternator output wire, and the location of the voltage sensing is at the alternator output wire as it leaves the alternator.

From personal experience, there is no good way to short circuit the installation of the 3-wire alternator. I used one with the sense wire not connected. It did work but not as efficiently and effectively as with the sense wire connected. My estimation is that when the comparator circuit of the regulator does not have a sample of the electrical system voltage to compare against the reference voltage, it does a fuzzy logic sort of approach and adjusts the output to suit the reference voltage. Does work, but not a best practice.

Where the alternator output and sense wire is connected to the is very important for this alternator application.

The alternator output wire should be connected into the system the same as the original OEM charging system installation, as part of the power junction. This can be done by either removing the old charging circuit wiring in its entirety and installing a new power junction and associated wiring, or connecting the alternator output to the old regulator rectifier out wiring.

The sense wire can be connected at the same point as the alternator output wire because as the electrical system voltage fluctuates, the electrical system voltage will be sensed by the sampling circuit in the alternator regulator, compared against the internal reference voltage, and the alternator output will be adjusted by the control element as required to meet the electrical system requirements.

In a 3-wire alternator install, the output from the alternator is dependent on the sampling and comparator circuit, and the reference voltage. Having the sense wire connected at the same location as the alternator output wire will not be an issue.

The alternator output stays the same until a change occurs in the control element variable resistance. Connecting the sense wire at the same location as the alternator output wire “senses” the variations in electrical system voltage requirement be it an increase or decrease because the alternator output is static until a change in the electrical system voltage is sensed and used in the regulator to adjust the alternator output.

Without the sense wire hooked up, the alternator output is at reference voltage on startup. As loads are applied, the electrical system voltage will decrease, but there will be no voltage compensation by the alternator. Conversely, when the electrical system voltage is higher than the reference voltage, the alternator output voltage will not be reduced to compensate.

With the sense wire correctly connected to the electrical system, and the electrical system is at 14.2 VDC, when a load is applied and the electrical system voltage decreases the regulator will compensate and the alternator voltage output is increased to maintain the reference voltage of 14.2 VDC. When an electrical load is removed from the electrical system and the electrical system voltage is increased the regulator reduces the alternator output.

I can attest to how the system works when the sense wire is used or not, when the sense wire and alternator output wire is correctly installed and in the correct location in the electrical system as I have done both. Connection of the alternator output and sense wire is critical to correct operation of the 3-wire alternator install and the bike's electrical system, as is the alternator output wire for the one or two wire alternator installs.
 
I mentioned that I have real world experiences to relate to this thread.

First I must look at the electrical system as designed and produced. In the attached schematic:
gl1200 charge system schematic.JPG
you will notice that there are no loads downstream of the power junction except the battery.

All loads are after the power junction as annotated on the schematic and generally after the ignition switch. With this in mind, it would beg the question as to why we, as owners, would change this design and add additional/new loads using the battery terminals.

JoeBarTeam has been having difficulty getting the charging/electrical system to operate correctly for a few weeks. His thread is at viewtopic.php?f=12&t=12649. Through a lot of trial and error, he now has a functioning electrical system. He has incorporated a new series regulator from Roadcraft that is a significant improvement over the OEM shunt type regulator. Having done this he was still having issues with the voltage reading on the bike's installed voltmeter - always reading less than actual and would not compensate for electrical system fluctuations.

I have installed and used the same regulator from Roadcraft and used the same install instructions and that was to bypass the OEM wiring harness entirely and hook the regulator ground and alternator output directly to the battery. The alternator wiring - 3 yellow wires from the OEM harness are connected to the regulator the same as for the OEM regulator.

After having done this research, and with an understanding of how the electrical system should be connected and operate, I recommended that he connect the regulator output wire to the OEM harness red/white wire(s) and use the original wiring harness to provide power to the electrical system. In doing this, the voltage meter is now indicating the correct alternator output voltage - electrical system voltage - of 14.2 VDC and the regulator is compensating for the electrical system fluctuations. This is with no additional owner installed loads added to the system. Everything is well with the universe.

Now that the electrical system as a whole is working as it should, add a new load to the electrical system, owner installed driving lights - not to say JoeBarTeam did this. When these lights are turned on, the electrical system voltage drops 1 to 1.5 VDC and the electrical system does not recover from this added load.

If the electrical system voltage drops some 1.5 VDC , the electrical system voltage will be close to that of the battery and the battery may be providing supplemental power to the system, but not being recharged.

Having contemplated this issue, I responded with the following:

"The design of the GW wiring is such that it has a power junction - see pic:
This is where the red wire from the starter solenoid is joined to the regulator output wire(s) before the regulator output wire goes to the starter solenoid. I found this to be a key junction in the installation of my external alternator, and JoeBarTeam has corroborated this as well by changing the wiring of the new regulator to suit the OEM installed wiring harness. His electrical system is now working well, and the dash voltage reading is correct.

The OEM schematics are quite detailed regardless of the bike, and all loads are after this junction (upstream from the junction) and mostly after the ignition switch. This is designed specifically to achieve a well operating electrical system. The only power going to the starter solenoid from the alternator is to charge the battery back to 100% after which the battery only receives a trickle charge.

JoeBarTeam mentions that the voltage drops and stays low when the driving lights are turned on - I would surmise that the power feed for these driving lights is from the battery. Voltage drop of 1.0 to 1.5 VDC. What should happen is there should be a voltage drop, then the regulator compensates for this drop and the electrical system voltage should return to the mean electrical system voltage of 14.2 VDC, plus or minus of course, but as close as possible.

Since the regulator is visually not compensating for this voltage drop, I am inclined to think that the regulator is sensing a large voltage drop and comparing it to the regulator internal reference voltage of 14.2 VDC and is increasing the alternator output to compensate, but not achieving the aim of returning to 14.2 VDC. Since the electrical system voltage is not increasing and returning to the regulator reference voltage of 14.2 VDC (or close to), the current in the electrical system is probably too high and damage to electrical components could occur, including the internal alternator.

if the electrical system voltage is extremely low, in this case by 1 to 1.5 VDC, the alternator output through the regulator has to be increased to compensate. This is how a regulator works.

Since the electrical system voltage drop is 1 to 1.5 VDC when the driving lights are turned on and the alternator output is not sufficient to compensate for this drop - this is corroborated by the fact the electrical system voltage does not return back to the mean value of 14.2 VDC - two issues may be at play. Where the load is connected into the electrical system is wrong, or the driving lights are a huge short bleeding power off to ground.

I submit that the issue is probably where the driving lights get power from. In this regard, I would recommend that the power connection for the driving lights be temporarily attached to where the regulator output wire is connected to the OEM harness red/white wires. The voltage at this junction is 14.2 VDC and since all electrical components are rated for 14.2 VDC - if not and just for 12 VDC, there would be a lot of electrical component failures - I surmise that the system will react to the additional load and the electrical system voltage will be maintained at or around 14.2 VDC, not the 13.2 to 12.7 VDC as it is operating now when the driving lights are turned on. The power feed for the lights can also be as I mentioned in my previous post after the ignition switch, or from the red wire to the ignition switch, but upstream of the power junction as shown in the attached schematic. If the power feed connection to the driving lights from the electrical system is at the output from the regulator, or on the wire going to the ignition switch, it will be live at all times and this must be considered if a permanent connection is considered.

Just my thoughts on the issue."

I have not seen a response from JoeBarTeam, but hope he tries this potential fix - using his bike as a test platform :music: . Would use mine, but have already corrected the alternator wiring and how the power junction is being used. Looking forward to his feedback.

Cheers
 
One more real world/life experience and that is mine.

When the stator failed on my 1200, I was originally going to replace the stator and did remove the engine to do this work. Since I had the engine out and the rear cover off, I also decided to rebuild the clutch and starter clutch.

I had an issue with the stator I bought and returned it. Took a couple of weeks off for a trip home to Ontario, and when I came back decided to do the external alternator modification. Sourced the parts required and installed the external alternator. Put the engine back together minus one stator and after installing the engine back into the bike, I tackled the external alternator installation.

Fast forward a couple of weeks and started the bike up with the new alternator modification and it worked - I was very pleased with the outcome.

In doing the alternator modification, I removed all the old charging system wiring including the power junction. I took the OEM power junction out, commented about it in the thread on my alternator Modification thread. I hooked the alternator up as I though it should be, directly to the battery and out. The alternator I had was a three wire alternator, and I did have a 12 VDC switched excitation wire attached, as well as an indicating lamp. I purposely did not hook up the sense wire as I did not think it would make that much of a difference. Unfortunately, I was mistaken.

The new alternator did work, but the dash voltmeter always indicated a voltage lower than that at the battery. The dash voltmeter indicated a voltage of approximately 13.7 VDC - 0.5 VDC lower than actual. Every now and then it would creep up to indicate 14.0 VDC but would always go back down to the 13.7 VDC range.

Voltage in the electrical system would always decrease when additional loads were applied to the electrical system such as driving lights, heated clothing, rad fan (power pig that it is), and others, but would not recover as the electrical system should. For mew I was happy to see consistency and rode the bike like this for over a year.

I always had a nagging thought that I should hook up the sense wire, but I didn't because the electrical system was working. I went on two tours of BC , one solo and one two up, and the bike worked well. Had a couple of issues but nothing to pin on the charging system.

The last trip of the year, round trip to LA and back, I had an alternator failure in Redding, California. The Honda dealership there was excellent and got me back on the road in less than 24 hours. I have posted on another thread about the help I received from Lee's Honda in Redding.

I still did not have the sense wire attached, but kept on and had a good visit with Dan Fillipi, family and friends. We returned to Dan's place and before I headed north to return home, installed a sense wire directly from the battery. Even though I did this, the dash voltage reading was still at 13.7 VDC, but the major difference was that the voltage stayed fairly constant.

On return home I started doing maintenance on my bike, oil changes, front fork oil, etc, and at the same time rewired the electrical system to put back the power junction and wire the charging/electrical system as per the OEM design and information I found and came to understand.

The dash voltmeter now indicates the correct electrical system voltage, and when the electrical system voltage fluctuates because loads are added or automatically start (rad fan) - the regulator compensates for these loads and the electrical system voltage returns to a mean voltage of 14.2 VDC. I trialed this after redoing the wiring as per the OEM design by cycling the driving lights (2 sets) and rad fan on/off to see what the electrical system voltage was doing.

The electrical/charging system was behaving as it should.

Thanks for reading. Cheers
 
This finishes my posts regarding this complex subject. This is a long thread subject, but I hope it has been informative and a good read.

I have posted this as information for those of you who are inclined to read these, and as my understanding of the 1200 electrical system. it will now form part of the other short articles I have done for myself to enhance my understanding of the Honda GW, specifically my '85 LTD. I find it very satisfying to further my understanding of these venerable vintage bikes.

Enjoy! Cheers
 
Still researching and updating the information I have regarding the electrical system. The latest gem I have found is a graph comparing a shunt regulator versus a series regulator for a Triumph. The thread: https://www.triumphrat.net/speed-triple- ... grade.html is a great read.

Here is the image:
StatorCurrent.jpg
(Image/Data courtesy of posplayr as tested in a Suzuki GS1000)

This is the only graph I have found that illustrates the difference between a shunt RR and a series RR.

Other series regulators:

SH775: https://www.remotemoto.com/articles/drz ... r-upgrade/ https://www.shindengen.co.jp/product_e/e ... talog.html

Here is another thread regarding the install and report of a Shindengen series regulator SH847AA: https://www.triumphrat.net/triumph-super ... ation.html

Lots of information out there, and I'm always looking. Want to find this poster called posplayr and read his information, think it would be quite informative.

Cheers
 
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