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I have an 08 FLHX that has the right running light out. Just the running light. Turn signal works.
I swapped the bulbs and they both work on the left side. So the bulb is good.
I swapped the connectors at the circuit board and the issue appears to stay with the right side pins on the tail light circuit board. Both running lights work on the left pins, but not on the right pins.
This is where it gets strange. I checked ground and voltage on both sets of pins. Both have ground, and both have 5.8v on the hot pins. However, as soon as I plug in the light on the right side, the voltage on the right side hot pin drops to zero. At first I thought the right side connector was bad or had a short somewhere but it works just fine when I plug it in on the left side. I also checked the solder joints on the circuit board and they appear to be solid, with no movement. Also, wiggling the connector does nothing.
What in the world could be causing the voltage drop when I plug in the right side connector?
Ive included a few wiring diagrams in case it helps.
That's what I thought too. But they are def running lights. They do not light up with the brakes. I don't think they ever did.
### CORRECTION ###
I just checked and the left one DOES act as a brake light! I never noticed before. Isn't there some sort of controller you can add to these bikes to make that work?
Last edited by danny1975; Oct 7, 2023 at 05:43 PM.
That's what I thought too. But they are def running lights. They do not light up with the brakes. Isn't there some sort of controller you can add to these bikes to make that work?
Yes a run brake turn module
find it if it exists it could be bad.
Any idea where it might be installed? I think I found one online so I might know what it looks like. Under the fairing, under the seat, under the side covers?
If you understand connections you can make it do different things.
My lights were turn only, I replaced them with 3 wire lights where I could either do
Run/turn or run brake. I added the module and connected run directly to lighting
and ran brake, turn through the module.
My rear OEM lights were 1 wire for turns. they use the frame for ground.
Harley changed this around 1997-98 started adding a ground wire to the lights for reliability.
My new lights are 3 wire. Run, ground and the third wire is for either turn or brake, that's why I added the module.
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Weird Lighting Issue
