Junction Box Wiring Kit for Wiring Up Trailer With Brakes and 7-Way

Published 06/08/2023

Products Featured in This Question

etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector

(361)

$56.03

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

Question:

Hi I have an 8x10 trailer that I need to rewire. I have brakes to put on my trailer. I want to ensure I can use 4 pin and 7 pin. What wire harness do you recommend.

asked by: Donald J

Expert Reply:

Are you looking for a wiring harness for the vehicle or the trailer? You normally wouldn't put a 4-way and a 7-way on the trailer as you'd pick one or the other based on if the trailer has brakes. Since yours is going to have brakes you'd want a 7-way instead.

For installing a 7-way on a vehicle the easiest solution is to use the etrailer 7-way junction box part # e99011. This mounts on the trailer and provides a 7-way to connect to the tow vehicle. The trailer's lighting and brake circuits would then run to the junction box which gives a cleaner install. For lighting functions you can use a lighter gauge wire but for the brakes you'd want to uses 10 gauge wire like # 10-1-1 which we sell by the foot.

I attached a help article on adding electric brakes to a trailer for you to check out as well.

expert reply by: Jameson C