[dennis hogan]

I know that this won't fix your A/C but might keep it from running so hard.When we go camping here in south east Texas ( Galveston Beach ) The only shade there is on the bottom of your flip flop's. I went to Home depot and bought a couple of roll's of insulation (like the one you put in your truck windshield) to help cool the camper and just cut to size and place between the glass and window shade. MAN What a difference it makes. Don't leave them in all the time just when the sun is on that side of the camper.
My A/C works good just trying to reduce as much heat from coming in. Give it a try .
Good luck Jeff.