Wiring a 7-Way Connector for a Trailer With Surge Coupler

Updated 10/11/2024 | Published 07/08/2009

Question:

I just purchased a boat trailer with a 7 pin plug. The trailer has surge brakes, so I need to send a signal to unlock the brakes when I back up. It was suggested that I run a wire from the backup lights to the 7 prong plug. However, I am unsure what terminal to use on the car side plug. Thanks for the information.

asked by: Dean H

Expert Reply:

You received the correct suggestion. Connect the center pin of the connector on your truck to the reverse light circuit, and the surge coupler will disengage when the vehicle is shifted into reverse.

expert reply by: Mike L

Chuck

8/30/2024

Mike, I have the same issue. I am switching out a 4 pin for a 7 pin so I can just plug it into my 2007 chevy silverado 2500HD. So if I understand you correctly I just need to run a wire from my accessory light pin i.e. center pin to the surge brake so that it disengages when I want to back up with the trailer in tow. I have a distribution block mounted to the frame of my trailer. Can I just run a wire from my reverse pin to the surge brake and have it do the same thing? All the pins should continue with the signal when connected at the bumper.

Mike L.

10/11/2024

@Chuck Assuming the center pin on your truck's 7-way is active (goes live when transmission is shifted into reverse). If you wire the center pin of the connector on the trailer to one wire on the reverse solenoid and ground the other solenoid wire, you'll be good to go.