A/C Pressure Switches

[Ray Davis]

Well, the Air Conditioning repair saga just keeps getting better and better. So, the guys at Prevost call me today. The a/c compressor switches on my coach are so old they cannot tell the numbers to know what the switch settings should be. They asked me to talk to Country Coach.

CC tells me that this is a standard Prevost compressor. I say it's not, and that we've already ordered one from CC. The tech at CC is floored. And then a stroke of luck. He looks out in the parking lot, and there's a Prevost conversion, similar era as mine, and the tech takes a walk out to the bus. Guess what, the same setup that I have.

But, in that coach too, the switches are so old, they cannot read the numbers, and the tech doesn't have any documentation (yet) for those.

SO, IN THE MEANTIME

I'm wondering if any CC owner out there (circa 1992-93 or so), which has the A/C compressor which sits atop the alternator (tandem belts). Do you have any idea of the pressure switch numbers, OR the values that the lo and high pressure switch cut out at?

Enquiring minds at Prevost (and my house) want to know!!


Thanks,
Ray

[MangoMike]

Ray,

You need to post this also on Prevost-stuff.com.


Good Luck.

Mike

[Jon Wehrenberg]

Ray, post or PM to me every piece of information you can about your coach. Include the serial number (the letter and four digits), model year, anything you can describe about the configuration back there by your engine and AC compressor such as where it is located, how it is mounted etc.

I will take the disc Jerry distributed at POG and do as good a search as I can to see if I can pull up the parts list and drawings. I may need to bug you for additional information, but I can tell you that I just did that research for mine, and the information was so well detailed that I was able to learn the pressure switch part numbers and the pressure range.

I can't promise I will be successful because I can go out to the garage and look at your coach, but I will try.

A general comment for what it is worth. I will be looking at the same data the Prevost parts folks have so if they cannot find it they are either lazy, or they literally cannot find it because over the years yours was changed from standard.

[Ray Davis]

Thanks Jon, PM'd with info. I hope it helps.

[Jerry Winchester]

Jon,

If you get hung up, I have the complete wiring and pneumatic schematics, but they are pdf files and they are MASSIVE, but if there is a wire running to it, you can find it.

But I can't believe that Prevost doesn't have CAD drawings. They are all done by hand and not very well at that. Go figure.

[mike kerley]

I'll check our 93 this afternoon. I'm sure I have the same set up as you. They moved the switches from the old compressor to the new when it was installed last year, so they should be the same. That's no guarantee i can read the numbers either.

I'll do my best to get you numbers today!

Mike

[Ray Davis]

Thanks all. Mike, I can't believe that CC was stunned when they found another coach configured like we had been describing over the phone. They kept insisting that (1) the dash air came from another compressor on the left side of the bus and (2) the compressor on the right side (which was only galley and bedroom OTR) was a stock Prevost unit.

They were quite surprised to find out otherwise!

I would bet your coach is just like mine.

[Jon Wehrenberg]

Ray,

I came up empty. I cannot locate a driver's air compressor driven as you describe, and the two listed, one pre "R" serial number (which yours falls into) and the post "R" serial number compressors are driven off the cooling fan right angle gear box.

Neither have pressure switches.

I'm leaning towards thinking yours is a CC component, and if CC is confused it may be possible that somewhere down the line someone changed it out and substituted for what you have.

Jerry: Perhaps your drawings could reflect an AC compressor for driver's air driven from alternator belts, on the RH side of the engine. The coach is a 92 XL, serial no. N XXXX.

Sorry.

[mike kerley]

Ray,

Found numbers on the low side switch only. they are as follows:

071-534000-F01-06 3646-07325-08425

The second set of numbers was a little 'scratched up" so the #7 might have been something else.

The high side had a green colored switch, for what thats worth.

Lester at Ken Robertson RV in Lakeland Fl ( sponsor and POG member I believe) installed the compressor on this after another "technician" (selling dealer) destroyed the pulley on the old one trying to take the clutch off. New clutch and compressor were required. And, it does feed all three evaporators. What Lester did was plumb the switches in the lines going to the blocks mounted on top of the compressor as the new blocks would not fit the switches.

Hope this helps. My guess is just about any stock switch would work. Just getting it plumbed into the system.