Turn Signal Problem...Different Than Others

[rsmith8411]

Alright, before you fellows jump me with both feet about changing out the board to fix my rear turn signal problem, hear me out. Been there, done that. I have a 96 C3500 that has been plagued with left rear turn signal issues for the last year. I've replaced the board 3 times (T-H-R-E-E TIMES!) and now it's doing it again. Replacing the board fixes the problem...temporarily. Here's what it's doing now: without the headlights on, the turn signals work fine. With the headlights on, the $&$#@ think does the fast click thing. But, when I look at the lights, they are all working...only faster. I don't see any burned out. Now it gets weirder -- I switched the left and right light assemblies and it cures the problem (of course I can't drive it that way or I would in a heartbeat, although duct taping them in place has been a thought). When I switch them back, the problem comes back. If it's a wiring or a board problem, switching the left/right sides should make the problem move around, but it doesn't. Somebody HELP! I would just hang my arm out the window and signal the old fashioned way, but my problem is only at night, so I'm reduced to begging for help.

[twistedtech]

Just for crap's & giggles, have you swapped out the flasher a hd flasher? There may just be enough resistence in the wiring to freak it out. try it, why not.