Ground issues

[89-300ce]

Hello,

I think I'm chasing a ground problem on my 83 Interstate.

I puchased nice high power LED's for the brakes and signals. These are actually nice and bright and work great on a test bench. They won't work properly in the sockets. The brake lights work but the running lights don't. When tracing the problem I find that I have .02v on the brake circuit and blinker circuits when the brakes and blinkers are off. This seems to be enough for the internal circuitry of the 1157 LED bulbs to switch over to stop mode and dissable the running light mode. When I disconnect the sockets from the wiring harness and manually feed them the bulbs work just fine.

It looks like I am somehow feeding a little current into the brake circuit and blinker circuits but I can't find where. When testing on the front blinkers socket I removed all the fuses but the running lights fuse, disconnected the blinker relay, the signal stop module, removed all the bulbs except for the intrument bulbs, and I still have .02v on the brake circuit and blinker circuit.

I've just cleaned the main grounds connection at the battery to frame/engine mount. There are two other grounds connections shown, one in the fairing with all the other unused connectors and one by the fuse block. I can't find either of them.

Could someone explain to me where these other ground connections are or suggest what else I should be looking for?

Thanks

Jorg

 

[dan filipi]

The frame ground (as I know it) is a green connected under the front coil bolt to frame.

I'm not familiar with the fairing ground or where that is.

Could it be your getting the voltage from dirty connections passing a tiny amount of current at the brake light switches or turn signal switch? Just a thought.

 

[joedrum]

jorg this is always a pita....ive got some stuff going on with my 83 ......theres ground connectors in the lighting could be one ofthose connections ....who knows so many wires and all ...it makes you want to scream and act like a fool having fun... :shock: :builder: :rant: :rant: :doh: :swoon: :mrgreen:

 

[mcgovern61]

jorg this is always a pita....ive got some stuff going on with my 83 ......theres ground connectors in the lighting could be one ofthose connections ....who knows so many wires and all ...it makes you want to scream and act like a fool having fun... :shock: :builder: :rant: :rant: :doh: :swoon: :mrgreen:

Joe...you haven't seen wires until you open up an 1800! The space shuttle doesn't have as many wires as a GL1800! :smilie_happy: :smilie_happy:

 

[AApple]

This may sound silly, and I don't mean to imply you aren't intelligent, but...are you sure the bulbs are in the sockets correctly? No matter what anyone tells you, you CAN install 1157 bulbs in the wrong way. :blush: I've spent many hours helping folks with tail/brake light issues, only to discover the bulbs were not installed the right way. Even tho there are pins at different heights on the bulb base, they can be put in wrong.
I was having an issue with one of the LED bulbs in my brake/tail light flickering, and finally determined the bulb base was not thick enough to keep a good contact on the socket. However, if I turned the bulb 1/2 turn, it fit tight, but of course, it wouldn't work properly. I wound up sticking a short piece of a plastic tie strap in between the bulb base and the socket, and hasn't flickered since. Just a round-about way of proving that the bulb will go in either way...
just a thought...

 

[89-300ce]

Good suggestion and I did check the bulbs to make sure they fit correctly. I disconnected the socket from the harness and fed it manually to test the bulbs.

I've got the tail light bulbs working properly now and I think I've got the blinker circuit figured out.

The Honda thermal style signal relay allows the LED to short from the running light circuit to ground through the signal circuit when the signal circuit is inactive. This doesn't happen with the stock 1157 bulbs because these circuits are isolated from each other by the filaments. I'm going to have to pick up an electronic relay to make them work. I thought I could get by with the stock relay because I was using the stock incandescent bulbs for the rear signals. I thought it would just flash faster, which it does, but I didn't expect it to totaly mess up the led running lights in the front.

Jorg

 

[bk2valve]

I wasn't paying attention to this thread so just saw what you are talking about....I installed LEDs in all my light sockets including the instrument bulbs and , yes I did have to go to an electronic flasher unit....I generate all kinds of power now though. What a difference...
Glad you are finding the ground problems though..
Brian in NM

 

[89-300ce]

Well after scratching my head for a while here is what I've found out.
I'm not sure if all 1157 LED's are wired this way but if yours are maybe this can save you some time.

I spent some time researching LED's and decided to use SMD 5050 based 1157 replacements
https://cgi.ebay.com/ebaymotors/ws/eBayI ... OTORS:1123

Because I was uncertain of if they would be bright enough I only ordered 2 for the brake circuits (I have 4 brake lights) and 2 for the signals circuit. When I went to do a side by side comparison (1157 in one socket and LED in the other) the LED brake light was nice and bright but the running light didn't work. If the circuit was all LED's it worked fine but if I installed just one 1157 all LED's stopped working on the running lights.

When the LED was installed in the front blinker the running lights woudn't work at all but the blinker would.

I jerked around for quite some time until I realized that the LED running light circuit could short through any bulb connected in the adjacent stop/blinker circuit. Once the current had passed through the resistor used to dimm the LED for running light mode it was easier to go through the filaments in the adjacent circuit than it was to go through the diode. It took me a while to find this since the current is so small it didn't light up the filaments in the incandescent bulbs.

On the blinker circuit it was draining through the 1156 rear blinker and the indicator bulb.

The solution for me is to install a Schottky diode in the stop light circuit to the led to block this path.



That's as best as I can describe it or draw it. Your 1157 LED may already have a schottky installed when assembled. Mine didn't. It's a cheap and easy fix and these LED's are nice and bright but it took this noob a while to figure out what was going on.

Jorg

 

[dan filipi]

Well done figuring that out, current flows can be tricky!