If you are able to climb on the roof then go up and remove the top of the air conditioner. Then take a garden hose and clean off everything (the coils, the fan blades, drain pan, drain holes) Then close it back up.
Next go into the RV with a step stool and open the interior of the AC unit. It might just swing open, or you might have to pull off the knobs and remove the screws from the corners to open it. Clean any filters you find. If the filter is foam you can use a bucket of soapy water to clean it out. Use a flashlight and look up into the AC unit and clean off any fan blades using a vacuum cleaner with brush attachment. Let the filter dry out and then reinstall it and put the AC back together.
Last thing. If you are having freezing problems do not run the unit on low speed. Instead only run the fan on high to help keep the coils from freezing over.
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2001 Suburban 4x4. 6.0L, 4.10 3/4 ton **** 2005 Jayco Jay Flight 27BH **** 1986 Coleman Columbia Popup