Troubleshooting P3 Brake Controller Install that Causes Wiring Issues when Override is Slid

Question:

Hi. I traveled from Florida to Indiana to purchase a toy hauler. After leaving dealer, I realized my f150 was not equipped to stop trailer electric breaks. I found a truck and trailer place open til midnight and they installed this device for a hefty price. While he was installing, he said the device was lighting up red indicating an open ground and he may have to track it down through my entire truck. I said, cant you just ground it to metal under steering wheel. He did and it lit up green. After about an hour or two away, I realized it was not activating electric breaks. When I press the button to do it manually, all my electronics start going haywire. There are no numbers lighting up when I press breaks to tell me how much power I set. I tried running a ground directly from battery just to see if that was issue as I found a sticker attached to unit that stars do not ground anywhere else basically. Please help if you can, I paid over $500 and nothing working properly. I was on the road for over 24 hours so I just didnt realize anything at time til it was to late..

asked by: Patrick G

Expert Reply:

Sounds like the guy who wired your P3 brake controller part # 90195 did not use the correct circuits. Due to what you paid for the controller it sounds like he had to hardwire the controller to your truck and it didn't have a facotry 7-way at the rear of it.

You need to verify the connection of all of the wires of the controller to make sure they are ran to the correct place. Most likely though since the controller is powering on the power and ground are okay. That covers the black (power) and white (ground). So that leaves the red and blue wires. The red wire needs to be ran to a circuit that only sees voltage when the brakes are applied. This is what activates the controller to know when to start appying trailer brakes, and the blue wire needs to be ran to the 7-way of the truck to take the brake controller voltage and send it to the trailer's brakes.

If the vehicle had a factory 7-way way at the rear of it (a black, round trailer connector), all you'd need to install this controller is the correct adapter part # 22292 which plugs in under the dash. If you had a factory 4-way you'd need this plus the # 37185 which plugs into the 4-way and gives you a 7-way. From there you run a few wire to the factory wiring of your truck and your set.

Your installer may have gotten creative and done a number of things. Check out the help article I attached below that covers installing a controller in a Ford truck like yours and/or email me back with more info on your trailer wiring and now your controller is installed and I can see what's best solution.

expert reply by: Jameson C