Wiring a Trailer Brake Controller to the Ford Factory Harness on a 2003 Ford F-150

Updated 07/12/2013 | Published 07/11/2013

Question:

i have a 2003 f-150 and the brake controller pigtail. i have a hopkins brake power controller with 4 wires: blue, white, red, black. my factory ford harness has five wires: trailer to brakes-green, ground-white, illuminator feed-brown, feed wire from battery-red, and stop lamp-green. what is the correct way to wire controller harness to pickup pigtail? i have it wired as follows with controller wire color first: blue to blue, white to white, black to red, red to green. not for sure its correct or where to put brown illuminator feed wire.

asked by: Casey R

Helpful Expert Reply:

On a brake controller, the wiring has the following colors and functions:

White is ground
Black is 12 volt power to the controller
Red is input from the brake switch
Blue is output to the trailer brakes

The brown wire on the Ford harness is not used by the brake controller so you can tape it up and stow it out of the way. Based on the functions you have listed for the Ford harness you will connect it to the controller as follows:

Truck white to controller white
Truck red to controller black
Truck blue(?) to controller blue (In the question you said that both the output to brakes and input from stop lamp are green wires)
Truck green to controller red