Troubleshooting Electric Trailer Brake Controller Not Applying Trailer Brakes with Foot Pedal

Updated 04/13/2017 | Published 04/12/2017

Question:

my draw tite trailer brakes . works fine with manual control but nothing with foot brake. i have power to the blue wire but nothing on the red. i disconnected the blue wire but nothing. when i press the foot brakes should the power come from the controller or the post that the red wire connects to. this is on a 2003 gmc. i am thinking the controller gave up.

asked by: Gene M

Expert Reply:

The blue wire is your power output wire whether using the brake pedal or the manual override. The red wire is the brake switch wire and should be on the cold side of the switch. When you hit the brakes, you should have power from that red wire going to your controller and out the blue wire to your trailer connector. If everything is connected right, check both wires individually with a circuit tester like # PTW2993 while you hit the brake pedal. You may need to adjust the sensitivity on your controller as sometimes that can get bumped and reset too low. Since your manual override still works, the issue is not likely in the controller. I recommend checking your trailer brakes for a needed adjustment and testing the brake magnets. If all of this checks out and it still isn't functional, then I recommend replacing your brake controller.
I've attached some articles to help.

expert reply by: Jason S