Finding Brake Controller Output Circuit for Ford Expedition

Question:

Hello, I am in the process of converting my expedition, and I have lost the blue wire. I had the trailer brake installed in the cab, I can trace it to the first plug in, and into a wiring harness. There was a blue wire on the side of the wiring harness at the back of the vehicle, but that wire was capped. I have stripped it and connected it to my trailer and is not recognized by the trailer brake. I have ran my own blue wire, but I am hoping you can help me before I “reword” my expedition Thank you.

asked by: Nick

Expert Reply:

I wish we knew exactly which wire it is in the harness you have found but that's not something we have access to. So you can use a circuit tester like part # PTW2993 to test all of the wires that you have found while someone holds and releases the manual override of the controller as one way to find it or you can bypass all of that by running a 10 gauge wire like part # 10-1-1 from the 7-way to the blue wire of the controller and you'd be set.

expert reply by: Jameson C