Wiring in a 3rd Brake Light on a 1986 Chevy Pickup Truck

Question:

It is a 1986 chevy silverado stepside. I installed a aftermarket third light with black and red wires coming out. How do I connect brake light to work?

asked by: Pete S

Expert Reply:

Your 1986 Chevy pickup wiring has the brake lights and turn signals combined on the same circuit. If the truck did not originally have a 3rd brake light (they didn't become required until later) then you will need to wire the brake light red power wire up to a converter, # 118158.

On the input side of this converter the green wire will connect to the trucks right turn signal/brake light wire, yellow will connected to the truck left turn and brake light wire. White will ground to a bare metal surface.

On the output side the green and yellow wires will not be used and should be capped off and stowed out of the way. The red wire will go to the 3rd brake light red wire and the 3rd brake light black wire is the ground.

If the truck did have a 3rd brake light before then to determine which wire you will need on the truck use a circuit tester such as # PTW2993. Have someone step on the brake pedal while you test the wires to determine their functions and wire it up to the 3rd brake light accordingly.

expert reply by: Michael H