Brake Controller on 2004 Ford F150 Operates with Manual Switch, But Not With Brake Pedal

Question:

I have a 2004 Ford 150 and when I use the foot pedal brake the indicator light on the controller flashes continually but no trailer brakes. When I use the manual override on the controller the light is steady and the trailer brakes work good. Thanks

asked by: Percy F

Expert Reply:

It sounds like the red wire on the brake controller is not connected to the correct wire on the brake switch above the brake pedal. Use a circuit tester like part # PTW2993 (a voltmeter or multimeter would be best) and find the wire that carries a signal ONLY when the brake pedal is pressed. If it has any voltage at any other time, it is not the correct wire.

The reason the manual override works is because it bypasses the circuitry connected to the brake pedal and red wire. This means the power to the brake controller and the line to the trailer brakes are properly installed. Once you have found and attached the correct wire to the red wire on the brake controller, it should work just fine. I have included a video on testing brake controller wiring below.

You should also check the fuse for the 3rd brake light, as well. The red wire from the controller is ultimately tied into this circuit, and if the fuse is blown, the controller will not receive input when the vehicle brakes are applied.

expert reply by: Michael H