Trailer Wiring Harness

[Hikerdogs]

Over the years there have been a number of threads in various manufacturers forums addressing the lack of power for electric brakes at the trailer socket. Having read and participated in several I thought I'd bring some of the information over here.

For some reason most coach builders have chosen not to run the #10 blue wire from the Ford factory harness to the trailer socket at the rear of the coach. As far as I know Ford includes this wire on all F53 chassis. However most coach builders fold it back in the chassis harness and tape it off. It's frustrating to install a brake controler and have everything on the trailer work except the brakes.

I've even asked the Winnebago factory rep why this was the only wire not terminated at the trailer harness socket even though the wire was supplied by Ford and the termination point is standard on all 6 and 7 pin trailer sockets and plugs. The answer was " the wire is terminated at the dealership if the customer orders a brake controller or the dealership is aware that the customer plans to tow a dolly or trailer with electric brakes. The fact of the matter is very few technicians are aware that the wire isn't terminated at the factory, and even fewer know where to find it in the maze of wires under the coach.

For future reference the Blue #10 wire runs to within 4' - 6' of the rear of the coach in the original Ford factory wiring harness along the left frame rail. At the point the harness breaks off to go to the trailer plug the wire is folded back toward the front of the coach and taped off. It is neatly tucked back in the factory harness and can only be found by opening it at the junction of the main harness and the trailer connector harness.