How many of us are there? Owners of Dodge based RV's?

My 89 Dodge Ram 250 van has been having Air Conditioning issues. It still is not working that great even though having a new compressor installed four years ago. It is somewhat cool on the low setting but when I turn it up it is just room temperature (warm) air.

Any hints to tricks to try?

Note that the AC black rubber hose has a small bubble in it. I should probably have a pro look at it. I have also read that the slide from warm to cold setting could be messed up in the console?

Thanks,