Turn Signal Issues

[eazyglide]

Having issues with turn signals not working on a 76 Chevy c10 with a new painless performance wiring harness and everything else working fine mostly. To start, I unplugged headlights (just troubleshooting at this point) and put the truck with the park lights on and walked around truck and all but the front right park/turn signal works and this one does nothing. Thinking the bulbs should be good I put the hazards on and everything works correctly including front right bulb that was in question. No issues with hazards on. Move on to reverse lights, these work correctly. Move to brake lights, these work correctly. Try turn signals again left nothing right nothing. Think to check turn flasher, I believe this is good as i can hear a clicking when i engage turn signal/stops when off and its new (only reasoning to say this). Checked over all fuses and none are bad. Checked power going to purple wire/turn signal switch and I think i remember 9-10v readings. Turn signal switch was new as well from autozone, was a 'matching' 8 wire switch that seems to work and have other reasoning to think its working as it should. Not sure where to go at this point, I had similar problems on last wiring harness but it had no hazards/front right turn/park light instead. I have now swapped out just about everything I can think of. Also have video of hazards. Any suggestions?

 

[projo198]

I just fought this on my '76 K10.

Looks like I get to be the first to say it, but check your grounds. I added a frame, motor, cab and bed ground strap and it fixed a lot of these issues.

If you are hearing clicking in the relay with turns and 4-ways there is something wrong with either the wiring, bulbs or light receptacle.

To be honest for my left rear turn I gave up and ran a whole new wire to it. Only one I couldn't get working.

 

[eazyglide]

Grounds is only thing i assumed were good but ill go and sand every ground and add a few more to chassis-firewall and separate out some grounds I have stacked on eachother to new locations

 

[Jgonick]

Incandescent or LED bulbs? With incandescent- Front park/turn lights use a two filament bulb. One filament will blink with turn signal the other filament is the the park light. (brake lights are also two filament bulbs) Hazard lights are fed by a different power source than turn signal lights. On the turn signal switch connector- brown feeds power to hazard lights and purple feeds power to turn signals.

Check the bulbs (a filament might be bad causing right park light not to be on) and check the connection at the turn signal switch (especially the purple wire). If the lights are flashing correctly with hazards that means the problem is -not getting power from purple wire. If checking connection and re-seating the connection at the turn signal switch doesn't fix the problem, re-check to confirm voltage on purple wire. Is there voltage on purple wire at turn signal switch connection? If no volts- double check fuse. What type of flasher? thermal or electric? If it is electric the terminals might be reversed. -or possibly bad flasher.

If you do have roughly 12 volts on purple wire-
Could possibly be a bad turn signal switch even though it is new.

I believe painless uses the same colors as original wiring