Another thing to check ...
Another thing to check is the thermocouple that senses whether or not the coils are getting ready to freeze up. If you drop the cover and filter, you should be able to see up into the coils. Most brands have a thermocouple inserted on or into the coils. It is a small metal tube with two wires (usually white) coming off it. Some use some kind of bracket to hold it in place, but mine was just jammed in between two of the coils.
It fell out when traveling, and things froze up the next time I used the A/C. I simply pushed it back in where it came from, and things have been fine since ...
Bill and Kate
Stone Harbor, NJ
2005 Jayco Jay Feather 29N (Salty Dog House)
2005 Ford/Quigley 4x4 E350 Van 6.0 TD (Moby)
Reese Pro Series SC Hitch