I have a Dometic fridg in my 2005 motorhome and when I start my f

I have a Dometic fridge in my 2005 Lexington motorhome. When I try to start my fridge on auto the check light stays off for a few minuts and then comes on and the fridge will not cool. The last time I used the motorhome was about three weeks ago and the fridge worked fine. I know the motorhome is plugged into a live 110 volt recept. I don't know if this matters but the LP tank is on empty. I had about 1/4 tank of LP when I parked the motorhome and as I said the tank is now empty. The fridge has been set on auto all this time and the gas button is pushed in on the control panel as it should be to run on auto. Please help me if you can. Thank's