I do not recommend someone to tamper with propane connections or regulators unless you are knowledgeable with it. Propane is a "very" powerful gas. Set up properly it is Great. But dangerous if done improperly. Call a professional for your safety.
Make sure your water condensate drain line is flowing freely and not plugged up. Also make sure you have a fairly clean air filter installed.. before you look for more difficult answers.
I would suggest that you visit an ac specialist shop as all air conditioners( car, truck , house and yours all use the same principle of operation
because it is roof mounted in an RV may be a caravan repair shop that has an ac specialist in the workshop or a truck service shop that installs ac units in truck cabins would be a good place to start
Sounds like either bad reversing valve or to get you going during the summer someone may have wired it to stay energized all the time which would have been a thermostat problem.
Not familiar with this number. Can you better identify what the brand it is and what this is? But generally everything is repairable. The Tech's question might because he does know how to fix the unit or he just wanted to sell you a new one.
JohnL I’m happy to assist further over the phone at https://www.6ya.com/expert/w._c61c997d7bf3e6ae
It could be could be several things depending on what type of AC it is. is it a window unit, or a split system. Could be a bad thermostat or thermostat wire or bad board or a safety or wired wong.