How to Tap Into 7-Way Reverse Light Circuit to Engage Trailer Coupler Reverse Lockout Solenoid

Updated 01/02/2017 | Published 12/30/2016

Products Featured in This Question

Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(82)

$44.04

Adapter 4-Pole to 7-Pole and 4-Pole

(660)

$61.90

Hook Probe Circuit Tester

(62)

$13.33

Question:

I have a 2003 Tacoma put Hopkins 43315 and added Hopkins 47185 adapter, question is trailer has the solenoid if not actuated or actuacted will not let you back up. My 2010 truck has 7 pin connector no problem. 2003 has the above adapters do I hook truck reverse light wire to blue wire on adapter or the yellow wire on the adapter.

asked by: Rick W

Expert Reply:

It sounds like your trailer's surge coupler has an electric reverse lockout solenoid feature to disable the brakes when you reverse the trailer. On the Hopkins Adapter # 37185 you will want to connect the Tacoma's reverse light circuit wire to the purple wire. This wire includes a yellow butt connector for making that connection. Please refer to the linked photo.

You can either trace the Tacoma's taillight wires to find which one goes to the backup light, or you can use a circuit tester like # PTW2993 to test the wires at one of the taillight assemblies to find the one that carries the reverse light signal. You will need a helper to shift the truck into reverse (with the parking and foot brakes both engaged for your safety) while you apply the tester.

expert reply by: Adam R