AO

It's gonna be hotter than hell in Hell this weekend and just to mess with me, my air conditioning decided to go south... perfect timing!

I have freon (R-134) in the system, and the clutch appears to engage, but since the tubes feeding the firewall and the rear AC are warm, I'm assuming my compressor went south. Is there a tried and true way to verify if the compressor is... well... compressing? Could it possibly be just the clutch?

Looks like at a minimum a used/rebuilt compressor might be in order. But a used one is $350! Are there any less expensive aftermarket compressors that people are using?

the flyin' scotsman

Andrew...........talk to 928sRUS.

Roger is working on a 'kit'

Tampa 928s

Did you put a gauge on it? Your expansion valve may be sticking!

AO

Thanks Malcolm... I'll give Roger a call after I get it diagnosed.

I was thinking that too, but both front and rear AC are dead. The only thing common is the compressor, right? I don't have a gauge set. I may try to pick it up from HF this afternoon.

Imo000

When you clutch is engaged, does it spin the compressor or is it slipping? If its not slipping then the electro-magnetic clutch is fine.

I have a rebuildable (possibly good) compressor off the parts car that you can have for the cost of shipping, however the last time I got estimate for shipping it was ~$35. I’ve bench tested the clutch on it and it works fine also when manually spun, the compressor makes the usual pumping sounds and the bearings feel fine. However since the system was empty when I got the car, I can’t be 100% sure the compressor is good (but it’s good at least for a rebuild).

AO

I guess that's my question. I can see the clutch is engaging (visually I see it spinning.) How can I tell if the compressor is turning or not?

Imo000

Ahh ok, I didn’t get that from the first post. It’s rather simple to check. When the clutch is engaged the center (clutch) of the AC pulley will be spinning with the outer (belt pulley). If the centre is always stationary (regardless of the AC button on or off) then the clutch is not engaging. You can check to see if the clutch is getting power when the AC button is on. If it its not then most likely the clutch is gone and if not, then something else is not letting the system turn on. This could be a pressure or freeze switch. OR maybe the system is low on refrigerant.

Big Dave

If you have to rebuild, I wanna come watch/help. The compressor currently sitting on my garage floor needs rebuilding, too.

SteveG

You need gauges to tell you what is going on in the lines with the compressor running. Roughly, at say 85 degrees ambient on a 134 system, I had 70 psi on the low and 250 on the high and was getting cold air. Wally and others have posted on tracing voltage from control head to clutch. If you have 12v to the lp switch and jump it, hence 12v to the clutch and the clutch doesn't engage, then it is the electromagetic clutch or a broken wire. That wire can get misrouted and touch a belt? Remove the belt on the compressor. Turn the compressor by hand. Any resistance? If it spins freely, it's not compressing anything. Note: When it is compressing, there is not a huge amount of resistance felt, but you can feel the piston doing its thing.

Ed MD

Have simiar probem, suspect it is the expansion valve. Can this be changed without evacuating the system of R12? Ed

ROG100

Andrew,
From what you have described it would certainly point to your compressor.
You are not to low on R134a or your low pressure switch would have cut of the compessor.
Even with low freon I would expect a cooling of the pipes that lead to the expansion valve.
I sell a remanufactured Denso complete with clutch for $425 with a $200 core charge.
Let me know by PM if I can help you?
Best,
Roger

I am putting together a kit which will include the rebuilt hoses (barrier) and correct O rings along with an expansion valve and dryer.

69gaugeman

Andrew, Imre

I am in Guelph now and am heading back on Friday to meet up in Hell. I can bring the compressor along if that will help.

Bill Ball

No.

AO

Thanks Rod, but the 90-91 compressors are unique from what I understand.

69gaugeman

Ya so are you