What Would Cause Trailer Reverse Lights to Come On Whenever Trailer Connector is Plugged in

Question:

Hi, I recently installed this electric controller on a 2010 GMC Sierra 1500 with Factory Tow package. But now when I connect my trailer to the 7 pin connector on my truck, the reverse lights come on. When I unplug the trailer then the reverse lights turn off and work as normal. Did I connect something wrong? I followed every detail on the videos I think. Thanks for your help.

asked by: Jose Q

Helpful Expert Reply:

Somehow you have a short between the reverse light circuit of your trailer wiring and the 12 volt accessory circuit. The center pin is the reverse light circuit and the 1:00 pin of the connector on the truck is the 12 volt circuit. So what you need to do is go over the wiring of the trailer and see if you can see any shorts between these two circuits and fix as needed.

expert reply by: Jameson C