The 12-volt trailer feed, which is the pin that sits in the 1:00 position if you're looking at the front face of the 7-way connector on the vehicle is fed by the vehicle battery. If this connection isn't already made on the vehicle side, run a length of 10 gauge wire like # 10-1-1 which is sold by the foot from the 1:00 terminal to the vehicles positive battery terminal. You'll run that circuit through a 40 amp breaker like # 9510.
On the trailer side, you'll run the battery circuit from... view full answer...