Air Conditioning Question

[adamdegraff]

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

[jack14r]

If your unit has a freon leak and a local tech tries to vacuum and recharge it have him use the chart that is on page 5 that Joe posted on cruise airs demistified.Cruise airs are very sensitive to freon charge or undercharge.If there is a sight glass it should always have bubbles when the compressor is running,unlike home or automotive AC units.Cruise airs are fairly basic and many parts can be found at local supply houses.

[Jon Wehrenberg]

Adam,

Your SMX panel can do some diagnostics. Do the check and it is likely it will indicate you are low on R22 freon.

It can be charged by any capable refrigeration tech. Insist he charge it according to the pressure charts. As Jack pointed out they are sensitive to under or over charging.

You will know when it is right. The sight glass will not run clear, not will it run foamy. It will show a liquid with bubbles. All condensing units have sight glasses.

[adamdegraff]

Jon and Jack,
I assume this is the same on a Marathon? I see you both are Liberty guys. Just double checking.

Thanks,

Adam

[Jerry Winchester]

Adam,

All the Cruisairs are pretty much the same, so only the installation may be different. You can pull the bumper down easy enough and check out the condensors to see if it is plugged up. You can even put some gauges on it to see if it has a charge.

On the one I posted the photos of, it would come on but because the condensor fan was inoperative, the compressor would shut down because of high pressure. This was fixed when we installed the new fan motor.

I would not be afraid to open it up, but if you are in Virginia (we are there today and it is hot from hell) then maybe a trip over to the Cruisair gurus that fixed Mango's might be in order.

A residental AC guy might fix it, but generally then can't even find it, so there you go.

JDUB

[tdelorme]

Adam, the rear Cruiseair is most likely not behind the front bumper. My Liberty has two up front and the third one is mid coach. You might find it by looking for the air discharge opening under the bus. See what the ones in front look like and then find another opening that looks the same further back. Like others have said, any good A/C tech should be able to check and recharge the unit. Good luck getting it going. You need all three to stay comfortable.

[Jerry Winchester]

Adam,

Don't listen to Mel Torme. Marathon puts all three behind the front bumper. Geeze, these Liberty guys.......

[tdelorme]

Adam,

Don't listen to Mel Torme. Marathon puts all three behind the front bumper. Geeze, these Liberty guys.......

OK, so with all three up front how the heck do you have any room to work on um. Never mind, can't be any harder than working on the mid coach unit I have. I literally found it by accident when I took out the "entertainment center" in the second bay curb side to have a tool box storage area. Somebody post a link to the proper charge specs for a Cruiseair. Adam needs um and I'm to lazy to search it up.

[Jon Wehrenberg]

Despite how the Cruise Air installations may look I think both Marathon and Liberty set ups are fairly easy to service.

The Marathon has access via swing out(s), and the Liberty installation has sufficient room to access the valves. The run and start capacitors are also easily accessed.

If the fan has to be replaced or the coils need cleaning that may involve the disconnection and removal of the condensing units, but other than that given the amount of space available they can be serviced. If the compressor has failed, just remove and replace the whole thing, also fairly easy.