Binfordtexas wrote:
I realize I need a brake controller but I'm trying to figure out if the truck is already wired back to the bumper. I don't know how to figure that out.
At the 7-pin and 4-pin on the bumper, use a multimeter with the prongs between "ground" pin and the various pins to see if you have any voltages (With the engine running) See a standard diagram for which pin does what. The brake pin (blue wire) won't be live, but the others could be for brake and signal lights etc.
Your 12v power line (pin 4) should go from 12.x with the truck not running (unless your truck has an isolator--Chevs don't, Fords do-) to 14ish with the engine on.
Check the truck's driver's manual for fuse locations that are for trailer towing, to make sure they are there and the right sizes.
