Installing Brake Controller on 2002 Ford F-150 Using Ford Wiring Harness with 5 Wires

Question:

I want to hook up my tekonsha envoy brake box to my 2002f150 pickup I have a harness that plugs in under the dash it has 5 wires but the box has only 4

asked by: Terry O

Expert Reply:

You will need to wire the brake controller to the harness by function. Brake controllers only use 4 wires:

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

Your harness likely has a 5th wire for illumination but it will not be used.

The likely wire colors and functions of the Ford harness are red for 12 volt power, light green for input from brake switch, white for ground, dark blue for output to trailer brakes, and brown for illumination that would not be used.

expert reply by: Michael H