Where Does Blue Wire of Tekonsha 7-Way Harness 22117 Install on Tacoma

Updated 09/29/2025 | Published 09/24/2025

Question:

I bought the Tekonsha 22117 Trailer HarnesWiper my 2016 Toyota Tacoma. Its all installing fine, but not sure what to do with the body harness Blue wire. Instructions show it goes into cab to brake controller and a black wire with 30amp fuse back out to the battery. I bought the custom Redarc TPH-015 Tow-Pro Harnes and Tow-Pro Liberty Brake Controller EBRH-ACCNA. They are both plug in under dash and do not list any need, or way to use the Blue Body Harness Wire. What do I do? Should I just tape off the blue wire, or is it needed?

asked by: James B

Expert Reply:

Hey James, that blue wire does need to go to the brake controller install harness you have plugged in as it is what connects it to the 7-way once it's installed. The black wire does also need to run to the battery as that is what provides power to the brake controller.

expert reply by: Jameson C

James B.

9/25/2025

The separately purchased custom Redarc TPH-015 underdash Tow-Pro Harnes has a black connector on one end that plugs into the Tow-Pro Liberty Brake Controller. The other end white connector of the harness plugs into the existing truck connector behind kickpanel. There is a white ground wire out of the black controller plug, but nowhere with the custom harness to connect the blue wire (or a black wire) from engine compartment. Cutting and splicing the custom harness doesn't seem right, so I'm confused. It looks like it would be different if using a Tekonsha controller, or not using the custom Redarc TPH-15 (Tacoma) harness, for the Tow-Pro Liberty?

Jameson C.

9/29/2025

@JamesB Essentially you would be using just the ground wire and brake light circuit of the brake controller port and the other two circuits would have to be hardwired to the vehicle with one going to the battery and the other to the 7-way wire to carry the voltage to the trailer brakes.