Is it working on any other power source? Have you had it working on AC before? I had issues a little while back I couldn't get mine to work on AC.
Mine ended up being a lose connection in the fuse panel, we think. Although we weren't actually turning it on correctly to start with. I didn't realize that on the panel on the fridge itself, once it was turned on then the auto button pressed, the AC or DC button had to be pressed up or down (I can't remember) I thought just pressing auto button was enough to turn it to AC, but there was another step. This wouldn't be your issue to would it?
2018 Flagstaff HW27ks
2015 Jeep Grand Cherokee Overland