OTR failure

[jelmore]

Finally got to experience no OTR air using the generator and Cruise Airs. It was actually very nice. Mid 70s outside but lots of sun. Forward and aft units on and the bus was very comfortable.

So, no OTR air. Three indicator lights came on -- the air conditioning failure light, the low A/C pressure indicator and the high A/C pressure indicator. Turned off the OTR air, stopped and waited 5 or 10 minutes, started it back up and it worked normally for 5 or 10 minutes and then the warning lights came back on.

I'm guessing this is related to refrigerant charge, but I don't know. Maybe I only need to clean the filters. Probably a good place to start. I guess it could be something more serious. In Memphis, who would look at it and know what they are doing? If it is a leak, then I probably should trust Prevost with that repair, but can someone else gas it up, or is that futile?

Enjoyed seeing people we've met before and meeting some new friends on a quick overnight at Oysterfest. This is a good crowd.

[Jon Wehrenberg]

Jim,

It could be as simple as resetting the CB for the condenser fan.

First, determine if the condenser fan is running. It is the one on the passenger side. With the bus running and AC "on" just check to see if you hear the big blower functioing. If not, find the circuit breakers. I have no clue where it will be located on your vintage coach. On my previous one it was located in the top of the first bay, driver's side.

I have not had any AC problems on this coach so I have not gone looking.

The CB, if it needs to be reset, is a hard one to reset. I have to push on it with a tool because my thumb will not do it. It does not look like it is tripped if it is tripped. It is a big red one.

If it is not tripped it could be low freon.

[jelmore]

Thanks, Jon. I've got the Prevost maintenance manual for this system so I will go through and check the things I'm capable of checking, including filters. If it does need refrigerant, is that a normal thing for any a/c shop to do, or is that a specialized Prevost service item? I guess I should just call PAS or one of the service centers.

[Jon Wehrenberg]

If you get to the point where it does prove to need refrigerant any shop familiar with the large Carrier systems can handle the repair. Truck refrigeration systems are essentially like ours.

Certainly Prevost can repair it also.

It is not acting like it needs a charge. Based solely on your description I would guess the condenser fan is not working or the condenser coils need some flushing. Open the door and hose the coils from the rear.

[MangoMike]

Jellout,

On my 97 Liberty in the bay w/ the condensor fans there is a grey electrical box with a couple of old fashion starter solenoids that activate the blower motors. I have had two fail so you might want to check. As Jon stated, no cooling across those and you're done.

starter solenoid.jpg

[jelmore]

A quick reply . . . 8 lbs. low on 134A. That has been over the last year and a half, so the oily residue around a fitting at the receiving tank and the sight glass off the dryer are the suspects. They put in some uv leak detection dye for a later check. Filters were clean, coils clean, compressor clean, all fans working. Two hours on the road and all is well.

Have to report very good service at KenKool (a 12-bay big truck service shop) in Tulsa. Joe has lots of experience and after an off-the-clock(!) tour of the system knew just what to do. Total time 1.25 hours at $75. Also had the generator serviced for one hour at $55. Nice people, good work and a bargain. Same generator service at Prevost Nashville a year ago was 2.3 hours at $102. Go figure.