How to Wire Electric Trailer Brakes on a Boat Trailer

Question:

Hello there! Id like to start by saying thanks for the last helpful email :. I am going to be installing electric trailer brakes onto my boat trailer single axle within a week or so and after endless searches online I have not found my answer. I understand I need to run a dual wire jacketed to the brake assemblies. Black and white black meant to be blue to 7 pin connector and white ground. So once I run the wire to the one brake what connectors do I use to run wiring to the other brake? What is a good waterproof way to splice into the one brake and head to the next? Also, how does the ground work if Im running a ground wire out of the 7 way connector? Do I still need to tap into the trailer for a ground ? Thanks :

asked by: Patrick

Expert Reply:

To run the brake lines on the trailer, you don't need the dual cable. I'd recommend using 10 gauge wire, part # 10-1-1 which is sold by the foot. Run the wire from the trailer connector back to the axle, cut the wire and strip the end. Use a butt connector like part # 05732-2. Run a lead to power each brake assembly out of the other side of the butt connector. Use some liquid electrical tape, part # SWC50122 to seal the connection. At each brake assembly, the brake magnet has two leads. One will ground to the trailer frame, the other will connect to the brake power supply wire.

At the connector on the front of the trailer, the ground wire from the trailer connector would ground to the trailer frame, usually somewhere on the trailer tongue. This allows you to use the trailer frame as a ground wire. As long as the wires from the lamps and the brakes are securely grounded to the trailer frame, you'll have a good ground connection.

Unplugging your trailer before backing the trailer into the water is a good practice to avoid short circuits. I'll link you to our trailer wiring FAQ article, which I hope you'll find helpful.

expert reply by: Mike L