Its a ground problem.

The turn and brake lights are grounding through the tail light circuit. You can test this by removing the lens and carefully grounding the lamp base and then checking to see what the lights do.


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...