The Dometic fridge model used in our Westys uses a very common propane
control system. The same system is found in many other gas appliances of
similar vintage. Here are some links that help explain a couple of the
key parts to this system, the thermocouple and safety valve. The
explanations relate directly and convey the ideas simply.

http://www.rvmobile.com/Tech/Trouble/Tcouple.htm

http://www.rvmobile.com/Tech/Trouble/safety.htm

Mark