Which Wire of Brake Controller Carries the Output Circuit

Question:

Brake controller installation. I have completely wired up everything minus connecting the red wire from the break controller to the brakes signal wire. I am on able to get a reading on the white wire that was thought to be the brakes signal wire. If you could be in for any assistance for a 1999 Chevy Silverado break signal wire it would be greatly appreciated

asked by: Timothy S

Expert Reply:

The white wire of a brake controller is actually the ground circuit. You'll never see voltage put on this wire from a brake controller. The brake output circuit is the blue wire of the controller. The black is for 12 volt power and the red is for stoplight circuit.

If you connect the power and ground and then apply the manual override of the controller you will see voltage on the blue wire of the controller.

expert reply by: Jameson C