Ray all the Cruise Airs have sight glasses that should be running clear after you run the air for 5 min. or so. I just checked mine since we are heading out this week. I would start by checking them out.

Our bus air...we changed from r12 to 134a so don't know what to tell you about your bus air. it sound like there are so many people doing different changes to r12 hard to know. Sometimes I'm tempted to just jerk out my hoses and start over, but as long as I get cold air for a few weeks in the summer I think its easier to put off, I had just added a few more cans of
134a to the system, it must have a slow leak somewhere.

The only other thing on the cruise air is to see how it passes air thru the coils, if while you are running down the road your now getting good air flow you will now get cool air. I can only assume that the install thought of that, but its now always the case.