The product build sheet for your coach should be on the inside of a closet door or inside of a cabinet door. Those sheets spec out the model numbers of appliances installed on your coach. If you can't find that, try calling Monaco and give them the serial number of your coach. They have some records. If that doesn't work, go up on the roof, take the cover off of the bad AC and get the model and serial number off of the tag attached to the AC.
Marty