Full Size Jeep Network

Got a travel trailer and want to set up the wag as a just in case vehicle for it since it came with a universal harness. It won't be the primary tow vehicle. How do I wire this thing up? It's a 79. Controller is a Tekonsha Prodigy P3.

The controller should have wiring instructions. It probably needs a dedicated 10 gauge power wire with its own fuse to the battery (usually where the battery wire connects at the starter solenoid). You can piggyback off the brake wire under the dash to get the signal that you've hit the brakes. But make sure you get the right side of the switch. Then run a 10 gauge wire from the controller through the firewall and route it back to the trailer harness.

10 gauge may be more than it really needs but when it comes to something like that, I prefer to have more wire than I need instead of hoping the "just enough" wire won't overheat.

I can read the instructions for the controller itself, but I'm more concerned about what needs to be hooked up to the Jeep specifically. What color would the brake wire be?

I don't know the color off hand. But you can follow the wires to the brake switch. It's on the pedal assembly up near where the brake pedal pivots. There's two wires. One will always be hot, the other will only be hot when you push on the brakes.