I seem to have an ongoing saga with my turn signals.
I'm replacing the front turn signals.
I purchased some turn signals that only have 2 wires, so I soldered a wire to the lamp housing for the 3rd wire, which should work fine.

This is a used bike...and someone else had already replaced the front signals with some cruddy ones that I'm replacing. Unfortunately, the wiring job left 3 unmarked wires. It would seem that it "should" be easy to figure out what wires go where, but I'm having issues.

I would like to be able to use my multimeter to just simply measure voltages and get the right wire to the right place...but...I don't know what the correct voltages should be.

I've tried a number of configurations where it "almost" works...left signal flashes appropriately, but then when i turn on the right signal, both flash, or all lights seem to flash...

It's MADDENING...

and to top it off I'm an electronics engineer!...DUH

So lemme ask you troubleshooters this...

Let's say you have cut off BOTH your 3 wire front turn signals, without knowing which wire goes where, how would you start hooking it all back up?

W/o looking at an example... so get a pail of salt to pour on...
black and a stripe tend to be ground, color and stripe tend to be positive.
if only one sig is flashing then that one is hooked up right (or left as the case may be)
If all four are flashing, try another.
Do only one light at a time too.  unhook the ones you're not sure about.

Use your meter, set for 12 volt dc.... turn on the ignition, two wires should have voltage,...they're your front running lights, tape them off if you have single filament bulbs.
Then put on your left blinker,...check the wires for voltage... the one that reads is your left blinker hot.  Repeat for the right.
The last two are grounds...

That's what I'd do...
Try it,... and then tell me where I screwed up....

Forgot to say.... touch your negative probe to raw metal on the frame for grounding while you are testing....

"when ONLY the running lights are on, I should only see a voltage on ONE wire on a given side, left or right."

Yes...

Multi-meters are nice but can be a royal PITA for checking simple circuits. For something simpler try this.

Go to your local hardware store & buy a door bell, the old chrome style that uses a transformer. Pickup a set of test leads (or make your own) & attach one end of the leads to the bell. You now have a circuit tester that rrrrriiiinnnngggssss when you have power & has enough resistance to make a turn signal flash. Connect a lead to 12v+ & use it to check your grounds. Much easier than having to look at a meter or test light. Really works great for checking fuel pump circuits that only energize for a few seconds when you turn the key on. Or when you're checking trailer light circuits.

always,... I think...

Savage_Amusement wrote on 08/27/09 at 08:02:58:


THANKS!!!
I think there are some other electrical problems going on in my system, because even the running lights don't read 12V...they read somewhere around 9V
I'm gonna check all the way back at the battery. Assuming that across the battery itself I should read much closer to 12V

Savage_Amusement wrote on 08/27/09 at 08:14:11:


This is a used bike, and someone had already messed with some of the wiring, because I have been seeing other issues.

Maybe this is normal, but I see "ghosting" in the blinkers, in that, when a turn signal is on, I can see the running light slightly dim and brighten too, as well as the opposite turn signal.

Looking at the wiring diagram, I see no immediate reason why that should be the case...perhaps my flasher is going bad ? Any way to test/verify that?