[Jim]

High pressure Jim, I got that on almost every bus I owned, not enough cooling air. Common problem while on the road and running a cruiseair in 90+ temps. Had it happen several times even in a campground with high temps, had to spray water under the unit to keep it from high pressure failure.

[Paul]

Thanks, I recall your comment , now.

strange only one of the 3 having the problem.

all three units near the front of the bus.

I am parked will try to cool the pavement.

Jim

[Archived]

MINE also in traffic and some times parked. only my salon unit. and it has been rebuilt all new. my a/c guy said my new compressor is a converted one from dometic to run R22 . added micro air soft starts on salon and bedroom do not see any great improvements as of yet. my salon i added a electric fan on a switched thermostated control. that has solved 89% of p/s shut downs, costs less than $150 dollars. the fan has been used two summers and wouldnt be without it. CA are new to me. love them when they work. but they are like me any temps above 90 is too hot. and i live in the hottest part of the southwest desert. 122 f not uncommon this time of the year. in four corners right now. good luck.

[John]

I service my 3 CruiseAirs. We don’t use our CAs while driving down the road. We have Prevost OTR full bus AC/heat. We do use them regularly when parked on 100+ degree blacktop at the various race tracks we go and race at. Once one of my 3 units gave the HI PS after I had serviced it. Turns out I over serviced it(too much R22 freon). Never had the problem again.

Make sure the condensers and evaporator filters are kept clean.

[Jon]

This is not an answer for everyone, but it is effective.

It takes a lot of cool air flow to get maximum efficiency from CA’s. That amount or temperature of air flow is often not available so performance is compromised. The obvious and simple things to do to increase efficiency is to insure the intake air to the condenser is separated from the hot exhaust air. Baffles or flaps play an important role and you have to insure they are in place otherwise the air being drawn through the intake suffers from being mixed with hot exhaust air.

The area under the coach where CA condenser air is drawn is sometimes compromised by hot air radiating from a highway, or the bus parked and lowered on tall grass that restricts air flow. Another problem is parking on hot blacktop that is radiating heat from being in the sun before the coach parked over it. When that happens spraying water on that hot surface will help a lot.

But the overall best solution is to install a pressure switch in the condenser high pressure line, and when it reaches a certain value like 300 PSI or whatever you choose, use the switch to close a circuit to open a solenoid valve that opens to provide a pure water spray across the condenser coils. At least one member has done that. He lived in NV and he was able to keep his Marathon cool by using a water mist across the condensing coils to keep temps down.

It is not a big deal technically to do that, but the challenge is routing water lines, locating solenoid valves and dealing with the potential for scale build up on the condenser coils.

[terry]

I have done the same thing manually with the previous coach CA units. Bought a personal spray mister from WalMart that takes a hose connection and outputs through 2 tiny mister nozzles. Works like a charm! However, the hard water left stains where ever it hit and I am not sure what it did to the area between the fins or to the components on the inside of the cabinet. It never appeared to be a problem and it saved my butt many times including last Summer in Vegas at 115 degrees. I’m just pretty happy to have roof air here in CO. I haven’t had to turn on all 3 units yet despite the 95-100 degree temps.

[Marshall]

JON. i also have a mister on my one problem CA unit. momentary switch. i used a 2 gallon window washer tank and i only use R/O water and have not seen any water build up problems. your inline switch sounds like a good ideal. the mister seems to get me by on the traffic stops in hot weather. along with the electric fan stays on when driving on hot days.