Where Does the 12 Volt Power Wire Come From that Goes into the Back of a 7-Way Trailer Connector

Expert Reply:

On a vehicle side 7-Way trailer connector the 12 volt power wire comes from the battery if you are hardwiring in a connector and running the wires yourself. In a vehicle that has a factory tow package it runs through the power distribution box and is fused from the factory.

If hardwiring in a 12 volt circuit yourself you can use wire # 12-1-1, sold by the foot. The wire will first go to a 40 amp circuit breaker, # PK54540, and from the breaker to the positive battery terminal.