Currently having problem with the frig. I have a Dometic 4872 that is working on Gas but not AC. I am currently hooked up to 110 AC and when I put it in "AUTO" mode it kicks the gas mode on. Tried to turn gas off and can hear the ignitor trying to start the gas. I have had it in the electric mode once and it runs for a few minutes then the "CHECK" light comes on. It won't stay in "AC" mode.
Sounds kind of like it. I'll let others take over here, but basically you've got an electric heat-providing device to heat up the ammonia, just like the tiny propane flame does. Check to see if it's heating.
If it's heating, you've got cooling, but the electronics that sense what's going on may not be working.
I would suspect the control board or a short in the electrical (heater) element.
If you have a ohm meter you can check the electric element should read very low ohms also check the element to ground some times they come in contact with ground and appear to be shorted out when moving the element just a touch will fix it.
If it is the control board replace it with a Dino board.
Ok, Yesterday i wake up and the frig says its running on
AC. Before I went to bed it was indicating it was running on GAS. It seems to switch from GAS to Electric and back. I checked it again tonight after being gone all day and it is in AUTO mode with the check light on. I turned off the frig and started it again and it switched to GAS. Seems the thing is cooling as the freezer compartment is cold. As I sit here writing this I can here a relay or something kicking off and on and just checked it and it had switched to AC again.