I had a 1976 Dodge motorhome. My Fridge had the instructions right on it to run on propane. Mine, you had to pull out a knop then keep pushing/pumping another until the pilot light would turn on. There was a glass window to look through to see it lit. I loved running on propane and drove with it on. I have read where you can run your fridge on a 20 gallon propane tank up to 30 days. Very economical. I thought it kept the fridge more cold than electric.
If you have trouble lighting the fridge pilot, light a stove top burner for about 5 minutes then turn off. This helps open up the propane gas lines.
I never ran mine on electric or 12 volt (living quarters battery). I mostly dry camped. (No water or electricity)
Make sure you fill your gasoline tank first so you do not have to worry about turning off the propane when filling up.
: Everyone has their own opinion concerning driving with propane on. Do your research. (Yes, I am covering my butt -