How to Wire 5-Way Wiring Harness on Trailer to 7-Way Connector

Updated 08/23/2022 | Published 08/21/2022

Products Featured in This Question

Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End

(709)

$7.20

10 Gauge Wire - Blue Primary - Per Foot

(107)

$1.71

Question:

I bought a 5 way wire harnass with red wire instead of blue wire. Can i use the red wire for electric brakes? Wire is for a 18 foot stock trailer.

asked by: David N

Expert Reply:

It sounds like you're trying to wire your 5-way wiring harness into a 7-way connector like the # PK12706. On your typical 5-way wiring harness the blue wire is for the reverse lockout. I'm not entirely sure what wiring harness you have, but assuming the red wire was intended for the same function it is probably 18 gauge wire so I wouldn't use it for the electric brakes.

At a minimum you want 12 gauge wire for the brake output, with 10 being our recommended choice. Assuming you have the other functions you need with the rest of the wires you could add # 10-1-1 in place of the red wire for your brake output.

expert reply by: Robin H