Location of Tow Package 12 Volt Circuit on a 2006 GMC Sierra 2500HD to Install Battery Isolator

Question:

2006 GM 2500HD with Duramax Diesel Dual Batteries Where to Connect Isolator My truck came with the 7-way plug already installed at the rear of the vehicle and I want to add an Isolator. I am maintaining a battery in my trailer for my brakes and a marine battery to run lights and stuff when trailer is not connected to the truck. I am looking for where to tap onto the 12V source of the trailer harness under the hood to connect to the isolator. I am assuming at the fuse box I will find that 12V trailer accessory wire? Please help.

asked by: Randy B

Expert Reply:

Yes you are correct. On your 2006 GMC Sierra 2500HD there is a stud for the 12 volt circuit located at the front left corner of the power distribution box (if standing at the front of the truck looking at the motor). I have included a picture that shows it (as a red wire, the actual wire is likely black) and the fuse associated with it. I have also linked a help article, part of which will help with the 12 volt circuit.

expert reply by: Michael H