Now that the hot weather has finally arrived, I notice that one of my smx cruisair units does not seem to be working.

Just to clarify, my bus has a number of heating options and two different cooling options. (Probably like most of your busses do.) The system I am referring to is the one that runs when the bus in NOT running. Generator on, I turned on, one at a time, my front cruiseair, mid cruisair, and then my rear (bedroom) cruisair. Front and mid started to cool nicely after about 5 minutes. (was a little surprised how long it took them to start blowing cool air, but it is 95 outside right now.) Rear unit blew plenty of air, but did not cool the air at all, even after running it for 20 minutes. I switched it to the heat mode and found that it would not heat either.

I've never had the front bumper down to even look at what is in there. I saw Jerry's post with the pictures (Cruisair demistified). And honestly, I don't really even know where to start. I must warn you that while I am handy, I am an A/C neophyte.

Some thoughts I had....
-lay down the bumper and blow compressed air all over the place.
-figure out which of the three outside units is linked to the rear cruisair and see if it is doing anything different than the other two. (Can I run the units while looking at them?)
-call my local A/C guy and have him take a look? (I'm thinking that could be a bad idea.)
-post a new thread on POG and get some good advice before I do anything stupid. I'm a violinist and would like to keep all of my fingers, please.

Thanks for any advice.

Bus is currently in West Virginia. Close to Roanoke, VA, Beckley, WV, and... well, nothing else at all. I'm guessing there is a cruiseair technician and parts warehouse on just about every block, so this should be an easy one, right?

Have a great day y'all.

~Adam