I have installed a Brake controller on my 97 F-350 using the factory supplied Harness located under the center of the Dash. That went fine.

At the rear of the truck, under the bumper there are two factory connections. the first is the 4 wire, which has the extension to a 4-flat connection.

The second connector has 3 wires. I have Identified the Blue as the trailer brake line (used the old Multimeter to see the volt's increase with input from the controller) But I cannot ID the other two wires... Red and Black. I tested them for Aux Power, Reverse, Additional Brake signal... and I still can't positively ID them...

Any help would be greatly appreciated.

MK

 

There are two relays required in the PD box under the hood that power the battery charge and the reverse light circuits. Check that the relays are installed.

 

Ahhh... that explains No Signal... Excellent Info! Thanks Frank! I will check on that tonight.

I had it checked at the Trailer shop and they gave it the thumbs up. Luckily those last two aren't critical to my towing at the moment.

Cheers,
MK