you need to run 3 wires from the front to the rear to power a travel trailer. i used a 12/3 extension cord. i ran it down the frame rail. the 3 wires were ground, +12v for charging the trailer battery, and brake output. i ran wires into the cabin through the speedo cable grommet. i mounted the controller where my ashtray was. see library for pics, it is a 16 year old controller.... run the 12v power from the battery through a fuse, run the power through the controller through a 25 amp circuit breaker.... i f there is an issue, you will want the circuit breaker to reset instead of blow a fuse. i would reccomend the 7 pin/and 4 wire flat moulded combo plug, for it's convenience and corrosion resistance... the signal for your brake controller is labeled CHMSL, and you can find the feed in the fusebox on the left side of the dash, or under the rear bumper. do not tap into the wires from the brake switch. there are no factory 'plugs' under the dash for trailer stuff, as on the F-150.... HTH