Is 12 Volt Accessory Circuit Required on 7-Way to Install Brake Controller

Published 01/18/2017

Question:

Hi, I ve checked out my wiring on my 2005 Ford Expedition. It has a factory 4-pin wire going to the back, and the brake controller connector has the blue, red white and black wires which I think is all thats needed to hook up to the Tekonsha P3. My question is, why do I need to run an additional 12V power line to the back? Doesnt the blue wire coming from the controller provide power for the trailer brakes? I dont want any power to the trailer other than the standard tail/signal lamps. Thanks again for your expert help.

asked by: Rick M

Expert Reply:

If you have only the need for a brake controller output circuit on the 7-way you do not need to activate the 12 volt power accessory circuit. Those two circuits are independent of each other.

expert reply by: Jameson C