I have an 02 chevy one ton with a flat bed on it. the lights on the bed are not working. the light on the cab is working like it should. Ive checked the fuses in the cab and under the hood. Was wondering if the turn signal switch was bad would it affect the brake lights. I read on another post that it did on someones trail blazer. the truck sat for a couple years before I bought it, the flasher switch is not working correctly either, when I wiggle it the lights on the dash turn on like I have turned the key to the run position, fuel pump turns on too. thanks for any help.

 

I would do an electrical test on the wire right where it plugs into your bulb. I had a similar problem and found it to be that one of the wires was grounding out and after some electrical tape i havent had any problems. I'm not positive about your turn signals but for the tail lights i would go with the obvious first and since you already checked the fuses just check to make sure you are getting power back there and if not just follow the wires to your problem

 

agreed, start with the bulbs and see if you have power out of or to the socket

flatbeds get worked pretty hard usually so its not uncommon to have wires damaged in the back under the bed