Towing Question for a new 2015HD GMC Denali PU

[Mackinaw]

I currently tow a Saturn behind a 40' Country Coach and recently purchased a new pickup that I would like to be able to tow. Unlike the 2014, GMC states that the batteries need to be disconnected in order to flat tow once the transfer case is in neutral and tranny is in park. By doing this, I will lose all presets so wanted to see if anybody had a solution around disconnecting the batteries but being able to disable the steering lock and use existing 12v for my Brakebuddy?

Lastly, has anyone found a pre-made wiring harness the 2015 GMC Denali Pickup?

[Camper346]

We have a 2014 Silverado (new body style) and we DO have to disconnect the battery to flat tow. We have the touch screen radio and do not loose any presets, there or anywhere else on the truck. We simply put the transfer case into N, leave the key in the ignition, adjust the seat to meet the brake buddy and then disconnect the battery. Never have had a problem with the battery running low, even on a trip from NY to FL. We use an aux. 12 volt outlet that clamps on to the battery and then runs into the cab to the brakebuddy. Since Chevy and GMC trucks are identical under the hood and electronically I'm sure yours would be the same. Our manual says that we will loose the presets, but we never have.