holding tank heating pads
We did this on a 2014 Sierra 24SR. It is a somewhat intensive job due to the wiring to the panel not being installed from the factory. We purchased a pair of rocker switches for the panel from the dealership and ran light wire to the area near the tanks fused behind the panel where we picked up the 12 volt for the relays. At the tank area we installed the pair of 12 volt relays and ran one heavy power lead directly to the battery with a fairly heavy 12v breaker/switch at the battery, using the frame for grounds. When not needed for cold weather we switch that breaker off at the battery. The small automotive exterior relays at the tank are controlled by the panel switches. We chose the after market tank heaters that can be heated with either 12volt when traveling or plugged directly into 110 at a pedestal or extension cord from the outside outlet if running the generator with the 110 plugs stored in the water fill & drain compartment.
After cleaning the tank and installing the heater pads we sprayed the exterior of the tank with adhesive and installed a layer of reflectix to protect and provide some insulation from cold wind.
It all works well, but was a project to run the wiring.