Turning On Running Lights Activates Trailer Brakes on a Brake Controller in a 1999 Chevy Silverado

Question:

Have a 99 silverado and when i turn on the lights the trailer brakes come on. I put the red wire in the right socket. Double checked all the other wiring according to instructions. Any ideas?

asked by: Ray

Expert Reply:

This indicates a problem with the red wire. There are several wires that can carry the brake light signal, but only one that is a brake light only wire. the red wire should be plugged in right next to the white wire and above the black wire like in the picture I have included.

If it does not seem to work, you can use a circuit tester like # PTW2993 if needed to probe the wires on the brake switch located above the brake pedal. You can attach the red wire to the brake switch wire that shows a signal only when the brake pedal is pressed. If it shows a signal when the running lights are on or when the turn signals are on it is not the correct wire.

expert reply by: Michael H