Troubleshooting 7-Way Install Where Trailer Brakes Immediately Lock Up
Updated 05/01/2024 | Published 04/29/2024
Question:
Hi, I replaced the 7 pin wire harness cord and installed a new brake a way systems on my trailer. All the lights and turn signals work, but when I plug the harness into the truck the brakes on the trailer engage. Why, everything seems to be wired correctly. Blue wire- Brakes Black wire - Power positive + White wire - Ground Please help! Thank you, John
asked by: John P
Expert Reply:
Hey John, check the black and blue wire connections. It sounds like you may have ran the 12 volt accessory circuit to the brake output circuit which is locking up the brakes as soon as the connector is plugged in. Most likely it will be that you just need to swap the 1:00 and 5:00 pins of the wiring and you'll be good.
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John P.
4/30/2024
Yep, that was it. The brake wire on the trailer was red and the 12 volt accessory circuit was a blue wire. Totally weird, don’t trust the color of the wires, tone out each circuit.