Finding Stoplight Circuit on 2018 Volkswagen Atlas for Brake Controller Install

Question:

I have a 2018 vw atlas. I have previously installed the 4 pin setup and hitch. I am buying a trailer with electric brakes. I purchased the ETBC7 and a brake controller to upgrade to the 7 pin. The problem I have is that my atlas has no factory trailer wiring. I have to locate the cold side of the break switch for red wire on break controller. I have no idea where this is on vw atlas. I am hoping for the wire’s color and location if possible. Also any advice you might have on good spots on specifically the vw atlas for firewall access. Thanks!

asked by: John M

Expert Reply:

Your 2018 Volkswagen Atlas has factory brake controller wiring that you can use the part # TK22FR to attach to which has the stoplight circuit covered. Normally to pull off what you are wanting to do you would use a circuit tester like the part # PTW2993 to test all of the wires that run to the stoplight switch till you find one that has voltage only when the brakes are applied. We haven't installed a brake controller on your vehicle yet so we don't know the wire color or how to get through the firewall.

expert reply by: Jameson C