Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
What are you running a jumper wire to?
Have you checked all the fuses with a test light to make sure you have voltage on both sides of the fuses?
Can you pull the brake lights out of the rear and uplug them, then see if you have power on the white wire at the brake light switch with the brake pedal pushed don?
Can you do the test I asked you to do with the jumper out please.
Please give me just a few to look over the wire diagrams for your truck.
I have been looking over everything for you and have to say that the problem has to be in the wires at the tail light. the parking lights and brake lights are on totally different systems and only join at the tail lights. Do you have trailer lights wired into the rear of the truck?
You have a short in the wire harness, and I believe that it is in the wires near the brake lights them self. Do you have trailer light plug wired in to the wire harness?