Larry,

If your OTR air is Prevost OTR air then the compressor is over sized for motorhome applications. If the compressor requires replacement you might want to call one of the companies that specialize in bus air. It's likely they will recommend a smaller compressor. This will also be the ideal time to transition to R-134a. Many of us CC owners are satisfied with our CC OTR cooling capability which uses Prevost dash air and a similarly sized OTR air system supporting the main living area and bedroom. This just reinforces the fact the Prevost OTR air is oversized. Prevost's system is designed for a full window coach with 50+ people.

You also have the option of running the generator on hot days to run your AC powered airs. This is what the plastic coach guys do.