Here's a diagram of an RV rooftop A/C
![](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcS3Mj4vr0XnZ2dE8jNTkUBnmTKWYenBoCxPz2inKXZxpxQzZl3AGg)
Have you cleaned that Evaporator Coil and Drain Pan area, the Blue Coil to the left of the drawing, and the part below it? You need to remove shrouding to reach it, not just the plastic machine cover.
The outside Condenser Coil, Red Coil to the right, can be cleaned too. I haven't ever found much there, but this I DID learn: The edges of the Condenser should have air baffles to the sides of the plastic cover. This keeps hot air from being pulled back into the coil.