P3 Brake Controller Shows Output Short on 2005 Ford F-350 Towing 5th Wheel Trailer

Question:

Electric brakes are intermittent. Running lights Brake lights and blinkers work fine, just not Electric trailer brakes. Took out stock electric Trailer brake controller and had codes removed. Installed a new prodigy p3 with wiring harness. At first that brakes worked fine, then they quit. Prodigy says I have an output short. Hooked trailer up to another truck and towed for 300 hundred miles and all lights and brakes work fine. 5th wheel triple axle and brakes on all axles. Hooked up a meter to my truck to test voltage at plug, says I have power and plenty of amps. Hooked 5th wheel back up and towed for 5 miles, no problem first 4 miles, then it says shorted output and then I have know brakes. Towed 5th wheel with another truck and no issues with trailer. Only thing I can think of is I have a short some where on my truck

asked by: Tony

Expert Reply:

I would agree it does sound like a short on the truck. The most likely culprit is a dirty or corroded trailer connector. You will want to make sure that the truck side and trailer side connectors are clean and free of corrosion inside and out.

It sounds like you are using harness # 3065-P on your 2005 Ford F-350 so I doubt that it is the harness or where it plugs into the vehicle but you may want to check that connection just to make sure there is do dirt or dust in there causing this issue.

expert reply by: Michael H