Thread: A/C Not Working

Is possible the Electro Magnetic Clutch has failed therefore while it is spinning, it may not be actually driving the Compressor. Wiring fault or blown fuse or a failed Clutch.

NB. I am assuming the HSE has such a clutch assembly.

No idea why you are getting partial operation unless the cause is intermittent.

I don't think the gas is gone at that standing pressure,if its correct.

Unfortunately,the compresser could be shagged,not pumping,to stop suddenly,or an electrical fault thats stopping the compresser.

There is an unloader valve that goes in them sometimes,but doesn't sound like yours has those symptoms,and my Indie told me they generally fail in the later 3.0L D4.

UK cars the under car pipe work corrodes to rear AC and causes fail.

Originally Posted by Ralph1Malph

Hi All,
My A/C has stopped working all of a sudden. And I mean all of a sudden!
Cold Cold Cold not Cold!

I searched and read about a few things that cause this but thought I'd seek advice.

Obviously it could be low gas. I recently had the radiator and intercooler replaced, which necessitated removing the condenser and emptying the system.
I would have thought that a leak would have the effect of reduced efficiency over time.

Before I look into the compressor side of it, I was looking for an A/C fuse or relay, but I'm either a dummy or a there isn't one!

I do have a HSE so it has rear A/C which I believe is a second evap but still only one compressor

I put my Gap tool on and got the following results:
System pressure 787.5kPa; Compressor /motor current 212A; Evap temp 37.0 although did reduce marginally over a few minutes; Ext ambient 32.5.

I'm not sure what to think about the compressor current, that's stupid high, but maybe it's a gap tool thing.

Thoughts, suggestions?

Ralph

There is no clutch. It’s a displacement compressor so a valve varies the output rather than a binary on/off of a clutch.

Originally Posted by Ralph1Malph

I'm not sure what to think about the compressor current, that's stupid high, but maybe it's a gap tool thing.

From what I've been able to ascertain the "compressor current" seems to be a vague interpretation of the displacement valve duty cycle. On mine about ~235 is flat out and it comes back to ~100 at lower loads.

Your pressure matches your evap temp pretty much on the nose and the pressure is measured high side. Likely the displacement valve is jammed shut or the compressor is toast.

Originally Posted by DiscoJeffster

There is no clutch. It’s a displacement compressor so a valve varies the output rather than a binary on/off of a clutch.

Thanks DJ, I am not familiar with this noo fangled stuff, but one lives & learns.

I had poor and intermittent cooling on mine. Re-gas didn't fix, although gas was down a bit.
Compressor replaced and running cold now. I was surprised at how bad it had become when it came back to normal.
Happily done under extended warranty.

Originally Posted by BradC

From what I've been able to ascertain the "compressor current" seems to be a vague interpretation of the displacement valve duty cycle. On mine about ~235 is flat out and it comes back to ~100 at lower loads.

Your pressure matches your evap temp pretty much on the nose and the pressure is measured high side. Likely the displacement valve is jammed shut or the compressor is toast.

Thanks! Just as a matter of interest, is it 'easy' to replace a compressor?
I know it won't be, but I do have one lying around and would be great if I could do it on a weekend!
I have read that the displacement valve can be replaced as well. I better look into it!

Ralph