Where to Connect Trailer Brake Magnet Wires on a Tandem Axle Trailer Towed by a Ford F-350

Question:

My first question is do I need to run electric brakes on a tandem axle trailer to a 7 pin trailer plug? I have the brake controller thingy on my dash of an F 350. How do I connect the electric brakes to that? Both brakes have two red wires coming out of them. Any assistance you can give would be greatly appreciated.

asked by: Tim

Expert Reply:

Electric trailer brakes have electro-magnets and they will need to be connected to the 7-Way trailer connector in order to receiver power from the brake controller in your Ford F-350. Since your truck is already set up with a brake controller and trailer connector we need to just focus on the trailer side.

On your brake magnets one of the wires will be the power wire and the other will be the ground. It does not matter which is which. The ground wires should be attached to clean and corrosion free bare metal surfaces. The power wires will connect to the back of the trailer side 7-Way in the 5 o'clock position.

Once you have the magnets connected to ground and to the 7-Way connector you will need to test them out. Take the truck and trailer to an empty parking lot and get going about 20 miles per hour or so and use the brake controller manual override only, not the truck brake pedal. If the trailer brakes lock up then adjust the power down. If they do not lock up then adjust the power up. You want them to be at a point just under lock up.

I have included a couple of help articles that should also help you with this project.

expert reply by: Michael H