Red Wire For Trailer Brake Controller Has Power Until Brake Pedal Is Pressed

Published 09/15/2023

Question:

I read an earlier submission that reads...that the red wire should only go hot when the brake pedal is pressed. If this checks out ok, then the controller needs to be replaced. My red is hot UNTIL the brake is pressed, then the signal to it stops. What does this mean? TY for your time!

asked by: Dan

Expert Reply:

I see you listed the 2018 Nissan Titan XD as your vehicle. If you are using a Tekonsha Brake Controller # 90195 it would use a Wiring Adapter # 3050-P which has a red, white, black and blue wire. The red wire carries power from the vehicle brake switch when the brake pedal is pressed. The white wire is the ground wire. The black wire is the main power wire and the blue is the output for power going to the trailer. If your red wire has power at all times except when the brake pedal is pressed you either have a wire installed on the wrong terminal of the brake switch or the brake switch is faulty and needs replaced.

If you have a different brake controller manufacturer or a custom install be sure to verify how it should be installed since the wiring could be different.

expert reply by: Bud M