Question:
Will this work for 2021 AT4? GM says that the negative and positive both is supposed to be disconnected.
asked by: Eddie R
Expert Reply:
I checked with Roadmaster to verify, and your 2021 GMC Sierra 1500 AT4 is compatible and will work with the Roadmaster Automatic Battery Disconnect with Switch # RM-766.
The only caveat is if you have a diesel engine as the battery disconnect is not compatible with a diesel engine on any vehicle. In regards to the positive terminal being disconnected, I could find no mention of that anywhere. I took a look at the latest owner's manual available for the '21 Sierra and it only states, on page 394, to disconnect the negative terminal.
I have added a link below to a video install on a '20 Sierra 1500 for you to take a look at as well of the Roadmaster Automatic Battery Disconnect with Switch # RM-766.
Roadmaster Battery Disconnect with Switch for Towed Vehicle w/ Flat Tow Brake System - Gas
