My left rear running light (pancake) was out but turn signal worked so I bought a new bulb.

Not the problem, still doesn't work. Just to make sure swapped the left to the right, Left still out, right working correctly so its not the bulb.

Pulled off the Tail light lens and swapped the wires from left to right, problem moves.

So I get out and am following the schematic back and forth through pages and pages of wiring diagrams trying to follow the pin in and outs. Note: this is very tedious to me, I hate wiring diagrams so have to concentrate to follow pin number and plug numbers. Did I mention I hate doing this kind of stuff?

At this point my almost brilliant son who is a Computer Tech says "its probably just in the turn signal indicator relay, not a wiring problem," and jumps the left and right running lights together with a cheater wire to show me I don't need to follow the wiring schematic to fix it.

Now both are off but both turn signals still work.

Meanwhile almost brilliant son has someplace to go urgently and departs before I can get to him to try and strangle him, this is why I say he is almost brilliant. He know when to leave.

Will be going past the Harley dealer so I can pick up a new relay if that is what it is but wonder if it truly is the relay.

Has anyone else run into this issue if so is there an easy fix, such as kill power to the bikes computer and let it reset?

Could the signal relay go back to a normal state if son only turned this portion of the relay off?

Or do I now have a Signal relay with a burnt diode thanks to almost brilliant son?

I really hate troubleshooting wiring issues

 

You need to tie down your son! He got part way there, so get him to finish what he started. Most 'wiring' issues are actually mechanical. Another possibility is you have a damaged wire that is giving a false ground. That's a mechanical problem - stopping the electrickery from going about its lawful business!

 

Any damage to a wire before the component is not a false ground, it is a short to ground.

The fuse would blow.

OP, what do you mean by pancake?

Is your bike a US model or International?

The wiring diagram shows running lights at the tail lamp, and some models on the tour pack. Not at the rear turn signals.

The turn signals and the running lights are not the same circuit.

The turn signals are controlled by the turn signal module.

 

Bike is an 08 Ultra Classic. Pancake is the large yellow running light under the Tour Pak, supposed to operate as both running light and turn signal.

The rear running lights have always been on until recently when the left went out...now both are out but turn signals still work so I know bulb and receptacle for the bulb are functional.

What gets me is right side worked until he tried to jump across them. Sounds like a pair of diodes in a relay somewhere but I don't know where that somewhere might be. In Solid State stuff I know just enough to get into trouble.

 

Oops, double post

 

Bump...Anyone have any other ideas?