Tommy47,
That was years ago that this happened to me so my memory as to exact costs will be fuzzy. Actually I didn't tell you the whole story but along with other symptoms, the excessive heat caused the ac hose to blow off and the entire system got contaminated. I replaced the compressor and dryer and still couldn't get the ac to work because the expansion valve was plugged. When I brought the rv into a Ford dealership for repair they changed the expansion valve, evaporator, spark plugs and catalytic convertor for something like $1700-2000. I got the vehicle back and it ran better but not right so I took it to an ace mechanic in town who changed the 02 sensors and the idle control valve and THEN it ran perfectly. That cost me around $250.
I also want to mention that when all this overheating was occurring, the pressure relief valve for the propane tank would pop open and release propane for awhile. One time I was at a service station getting gasoline and the propane valve popped open releasing propane and it sounded like a missile taking off. My wife and I grabbed our wallet and purse and ran as fast as we could. Tommy, get it fixed!