I worked at a major RV dealer - service facility for several years and a master RV technician I trust has always said it is best to leave an RV fridge running all the time. His reasoning is that the ammonia based liquid in the cooling unit has an anti-corrosion additive which if left "on" and circulating prolongs the life of the cooling unit. When I worked there as a service adviser I saw a few cooling units that had corroded through requiring replacement.
It seems the advice on this subject is split between leave "on" and turn "off" when not in use. Don't really know if one was is really better than the other.
