Troubleshooting Trailer Brake Controller Power in 1994 Ford F-250

Question:

I have no power to the brake controller box. I only have power when testing with the break pressed. Looking for troubleshooting suggestions

asked by: Abby

Expert Reply:

The black wire to your Draw-Tite Activator II Trailer Brake Controller 5500 carries +12V power to operate the controller and connects to the battery positive terminal through a circuit breaker. This wire should carry 12V at all times.

The red wire carries the brake light switch signal that tells the controller to generate an output signal for the trailer brakes. This red wire should carry a signal only when you press the brake pedal on the truck. It connects to the COLD side of the brake switch, the side that carries a signal only when you press the brake pedal.

The white wire is ground and connects to the battery negative terminal; the blue wire is the controller's output signal that gets routed to the 7-way socket on the truck.

If you confirm that your wiring installation is as described above (and in the linked article) then your controller may be damaged. Since this is a time-delayed type controller when it is wired correctly you should get a brake output signal when you press the manual override AND when you press the brake pedal.

If you do need to replace the unit I suggest the Prodigy P2 # 90885 and the mating wiring adapter # 3035-P.

expert reply by: Adam R