Stator testing

With the battery being relocated by the PO into the LH pannier I decided it would be wise to check the stator. As I also had the heads off it would be a lot easier to pull the engine to replace the stator if need be.
Battery cables in LH pannier
On my 86 1200A the stator leads are in 3 bullet connectors but the testing procedure is the same for the 3 pin connector or just the phase wires from the stator.
Phase pair 1
Phase pair 2
Phase pair 3
The multimeter is set on the lowest ohm scale for testing and I am using my cheap multimeter that I take with me on the bike so readings of 1 ohm and .9 ohm are acceptable. Using the multimeter you also need to test between each phase lead and ground making sure that you don't get a reading which would suggest that the insulation is faulty.
To be more certain of the insulation and the quality of the stator windings I prefer to do a high current test in this case using a 55w spotlight and 12v battery in place of the multimeter.

nice post

Tony, can you explain the reason for high current test. What does it mean and what it is telling us.

You can still have a circuit but it may not have the ability to flow the current that is required. I actually short the leads directly to a battery(12v) to check the integrity of stator windings but you can only do it momentarily otherwise you could burn out the stator. I decided to use the headlight bulb because you cannot damage the stator if you leave it in the circuit too long. You can increase the test current by increasing the wattage of the bulb that is parallel in the circuit. The stator windings are connected to the stator leads inside the engine case as Joe found out when he was looking for faults. A high current test would find that fault, poor insulation in the windings or a break in the windings themselves.

yes it seems this test in the best way possible as load is in the testing ... i searched the web big time back then on stators .. and it seems this test was second to none for actually predicting the stator will charge when loaded

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=125032#p125032:1156l00i said:

Ansimp » Fri Jul 11, 2014 5:41 am[/url]":1156l00i]
You can still have a circuit but it may not have the ability to flow the current that is required. I actually short the leads directly to a battery(12v) to check the integrity of stator windings but you can only do it momentarily otherwise you could burn out the stator. I decided to use the headlight bulb because you cannot damage the stator if you leave it in the circuit too long. You can increase the test current by increasing the wattage of the bulb that is parallel in the circuit. The stator windings are connected to the stator leads inside the engine case as Joe found out when he was looking for faults. A high current test would find that fault, poor insulation in the windings or a break in the windings themselves.

Click to expand...

So if I read you right your grounding one lead of the bulb then running 12 volts into one yellow wire and out another yellow to the light then repeat with all three yellow wires?
Something new to me, I usually check voltage with the yellow wires unplugged and bike running..Didn't know there was other test to perform.

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=125032#p125032:1bx9frhn said:

Ansimp » Fri Jul 11, 2014 10:41 pm[/url]":1bx9frhn]
You can still have a circuit but it may not have the ability to flow the current that is required. I actually short the leads directly to a battery(12v) to check the integrity of stator windings but you can only do it momentarily otherwise you could burn out the stator. I decided to use the headlight bulb because you cannot damage the stator if you leave it in the circuit too long. You can increase the test current by increasing the wattage of the bulb that is parallel in the circuit. The stator windings are connected to the stator leads inside the engine case as Joe found out when he was looking for faults. A high current test would find that fault, poor insulation in the windings or a break in the windings themselves.

Click to expand...

Sorry guys I definitely had brain fade when I said " parallel" as this is a series circuit. Polarity is not important, one lead off the battery goes into the one side of the bulb and out the other side to a stator leg/winding and then from the next leg back to the battery. So it is one big loop :yes:

I hope that makes it clearer now Jeff :thanks:
When in doubt check the big version of the photo for the circuit :doh:

Basically what this test is showing is a true reliable continuity through the stator coil winding.

Electricity is funny.
In simple terms, you can have electrical flow through a wire but as soon as a load is put on that wire, the flow can stop. A broken wire that has arced together will test good but may not be able to carry a load through it, or for only a short time.
This test is proving out that the continuous run of the wire is capable of producing a current, not just voltage.

Good thread! :thanks:

yep tony schooled me over and over during the hooch build

I was hoping to present this in a manner that would be useful in the future to anyone querying the integrity of their stator windings without the engine running.
With the AC voltage checks with the engine running that gives an indication of the magnetic field in the rotor as well as the integrity of the stator windings and connections.

Thanks Tony :good:

3 Wires disconnected
Testing A/C
wire to wire at idle 1-2 1-3 2-3
35
11
28

I will test with the wires connected and running, but I'm sure it's the stator because the bike will die the instant I remove the jumper cables.

With numbers like that it looks to me like a bad stator.
Usually an electrical system needs a battery to complete the circuit so disconnecting the battery may not tell anything.

I left the battery connected, it holds a charge but fails on a draw test, need a new one still.

Ok I see, voltage must drop too low to maintain a spark.

On the plus side of this. 1000, 1100, and 1200 stators will interchange with the possible exception of the fuel injected 1200 version. Not sure anyone has tried that one yet.

Mine is fuel injection, lol

Okay! Then maybe now we'll find out. However you do it will be a chore but if you go external alt. it will have to go somewhere and stuff will need moved, cut, removed.

I believe I'm ready for all that, only thing left in the way is the radiator. Marked the bracket I need to cut out of the way and I'm just about ready for the kit. According to Don, he has sold at least a dozen kits to those with CFI, so I feel confident that it will work out.