werid wiring

[watsontyson]

I have a 1960 c 10 swb pickup. I've replace the under dash wiring, cluster harness and the turn signal. The problem is whenever I apply the brakes, the right front turn light and the dash turn indicator lights up and the left rear brake light does not. Both turn signals blink correctly, just the brake side is weird. What did I do incorrect?? Thanks. Watsontyson

[Captainfab]

It sounds to me like you don't have good grounds at your tail lights. If necessary add a ground wire from the tail light housing to a spot on the body that you clean off down to shiney bare steel.

[kieth]

Originally Posted by watsontyson

I have a 1960 c 10 swb pickup. I've replace the under dash wiring, cluster harness and the turn signal. The problem is whenever I apply the brakes, the right front turn light and the dash turn indicator lights up and the left rear brake light does not. Both turn signals blink correctly, just the brake side is weird. What did I do incorrect?? Thanks. Watsontyson

If you do not have a good ground then the electricity will find the best ground it can. That's why one gets strange lights coming on at weird times. We Soldered a ground wire to every external light housing on my truck front and rear, added a grounding block (common gang which was grounded to the frame) No more ground problems........all lights are bright and no more chasing gremlins. Kieth

[ray_mcavoy]

^ I agree ... poor grounds can definitely cause some strange behavior. Especially with double filament bulbs where a poor ground allows the circuit for one filament to find a ground path though the other filament/circuit.

If you are still having problems after making sure all the sockets have good grounds, check the turn signal switch. The contacts inside that switch allow the turn signal to override the brake light on the side that needs to flash. So a defective turn signal switch can also prevent a brake light from working as well as backfeed power from the brake light circuit to the turn signal & dash indicator.

[watsontyson]

Thanks everyone. I replaced the left rear socket with a "not stock" one and that might be it, but the rear harness has been chopped into so many times I'm going to trace the wires back to the cab connection to make sure they're not connected wrong too. the turn signal switch is new, but I'll check the adjustment on the wire feed from the turn signal stick up by the steering wheel as well. Thanks again.