...
For now, I simply connected the 7 pin harness adaptor to the existing 4 pin connector and zip tied them together. I screwed the white ground wire into the body of the car. Later I will connect up the black wire (12v power) to the battery using the relay and circuit breaker listed in the parts section.
Fuse
The original trailer wiring installed by the dealer has a fuse in the truck near the spare tire.
...