Wiring Trailer with 4-Pole Connector for Electric Brakes

Question:

My trailer is wired with a 4 prong and i just put in a new axle with electric brakes and i want to wire it up. I have a brake controller. Help

asked by: Dave P

Expert Reply:

In order to wire your trailer so the new electric brake assemblies can be activated, you will need to first install a 7-Way connector.

I recommend removing the 4-Pole connector already on the trailer and installing a 7-Way like the Hopkins # H20046. You can use a junction box like # 38656 and 10 gauge wire # 10-1-1 (sold by the foot) to run the brake output circuit from the junction box to the brake assemblies. I have attached a video demonstration on this junction box so you can see exactly how it will work.

Each brake magnet on your trailer will have two wires coming out from them. One of the wires will ground to the trailer frame and the other will attach to the brake output circuit. It does not matter which wire you use for which function.

You will connect the wires going to your existing 4-way connector on the trailer to the appropriate locations in the junction box. The wires from the new 7-way connector will then connect using the same locations. I have included an image that shows the color wiring code on this 7-way connector along with the typical colors and functions for trailer wiring for you to take a look at. I still recommend using a spare 12V battery to test the trailer wiring in order to confirm the wire functions.

I have also included a couple of articles on trailer wiring and brakes that you may find helpful.