Stacy if you have the original Armstrong ac it can be repaired these are awesome units. If you go to the vintage airstream site and look under ac you will see a list of shops who repair them. Do not remove the cover yourself as they have a tendency to disintegrate.
If you don't want to repair it then get a Dometic penguin. Do not run these on anything less than a 30 amp circuit this requires a 30amp extension cord as well. Do not use a 20 amp cord
Lucky Dave, Denver NC