Troubleshooting Brake Controller Doesnt Detect Trailer after Installing Fifth Wheel 7-way Harness

Question:

Greetings, I purchased the bargman wire harness 51-91-410 for my 2011 ford super duty which has the factory tow package with factory brake control. once install all the lights work on the trailer yet my truck does not acknowledge the trailer connected so the brakes wont work. it is not my truck as I disconnected your harness and everything functions properly again. its almost as though because now it has 2 7 blade connections it sees one as open. do you have a solution? do I have to plug a non terminated plug into the stock socket for the fifth wheel to have brakes?

asked by: Scott

Expert Reply:

All the brake output circuit of your truck should have to see is a load on the circuit (from the trailer brake magnets), for the controller to say that it is connected. The issue has to be that the brake output circuit is not completed when the # 50-97-410 is installed on your truck. I would check for corrosion on the pins of the factory 7-way when the connector is installed as there has to be something that is preventing the circuit from going from the factory 7-way to the fifth wheel 7-way.

You can test this circuit by activating the manual override of your brake controller with a circuit tester like # PTW2993 on the output circuit of both 7-ways. It should see voltage on both, and if it's only working on the original then you know the problem is in the wiring of the # 50-97-410.

expert reply by: Jameson C