Just bought a 71 chevy 4x4 and tailights don't work. Got underneath it and looked and there was only one wire from the front of the truck to the rear. Found the rest of them and was able to identify the turn signal wires, the brake wire, and the taillight wire. Here's the problem. When I started reconnecting everything nothing would work properly. Finally after hours of combinations, here's what i came up with. I have the brake and signal wires together, the tailight wire alone, and the ground wire to the frame (yes i have a good ground, already thought of that). The tail light now works,and the brake and blinker light works too. But when I turn on the blinker, then hit the brakes it stops the blinkers and just shows a brakelight. Right now I'm only working with the rear left tail light and the other is disconnected. Any ideas on what I could be doing wrong?
A basic tool you need to check this stuff out is a small probe light. I has a ground clip wire and a pobe. You activate the circuit, ( turn the blinkers on ) and probe the wire to see if it probe light activates. The only way I've successfully tracked down this type of problem was, with wiring diagram in hand, check the entire circuit you are troubleshooting from end to end. Start at the beginning, check the circuit till you hit a harness connector, clean the harness contacts, and keep progressing through the circuit until you find a fault. You might also check your column harness to make sure that it's in good shape and no creative wiring was done there by the previous owners. DVal
HOW DOES YOUR TURN SIGNAL SWITCH LOOK. TAKE OFF YOU STEERING WHEEL AND SEE IF THE SWITCH IS DIRTY OR BROKEN. IF THE CONNECTIONS THERE ARE BAD IT WILL DO THAT. MINE DID THAT AND I BOUGHT A NEW SWITCH FROM YOURS TRULY CHEVY DUTY AND IT'S WORKED EVER SINCE.
Ok i figured out my problem. The tailight housing is actually my ground. When I put the assembly all back together, it worked fine (after I procured a wiring diagram). thanks to all for your suggestions and help
