Wire Gauge and Circuit Breaker Needed to Wire 12 Volt Accessory Circuit to Trailer Connector

Expert Reply:

To wire the 12 Volt accessory circuit on your 7-Way trailer connector, you should use wire no smaller than 12 gauge, although 10 gauge would be best. We offer the wire you need, the part # is 10-1-1, which is sold by the foot. I would recommend protecting that circuit with a 40 amp auto-reset inline circuit breaker, part # 9510. To wire the circuit, get a piece of the 10 gauge wire that will be long enough to reach the battery from the trailer connector on the rear of the vehicle. Attach one end of the wire to the number 4 pin on the trailer connector, and route under the vehicle up to the battery. Be sure to avoid any moving parts and areas that experience high heat, like the exhaust pipe and manifold. Once the wire is run near the battery, attach the circuit breaker to a convenient spot near the battery. Attach that wire to the post on the breaker labeled AUX. From the terminal labeled BATT, run another length of wire to the positive battery terminal.

expert reply by: Mike L