www.jec.org.uk

I don't think my air con works as it doesn't blow cold air. I just want to make sure that the system is working as it sould before I get the thing regassed.
I had a look at the air con compressor after the car had been running for a while. It was very hot today so I expected the compressor to start fairly quickly. I'm not familliar with this car's a/c compressor, but I've fiddled about with another car's. I was hoping to see the end part of the compressor (nearest the radiator/beyond the pulley) clamp down on the pulley as the clutch is engaged. If that is not the way this thing works, please enlighten me.
Also, is there a test button on the climate control panel that can indicate if something is not working?
Basically, I'm just looking for a checklist to work through to make sure the a/c will work.
Thanks in advance.

Had simmilar problem on mine when I first had it, no air con!

Took it to my spanner man, and put it on his machine, had a little gas in the system, just not enough to run it, so started to vaccum the system down, after 20 mins, got a little hissing noise, turned out the condenser had rotted through!

Changed the condenser and reciver/dryer on top of it, they had rotted together!
Re vacc the system, fill with gas and oil, and hey pressto! cold air!

I then find that the system has its own fault diag, just dont recall how to enter it? but that came up with a code for low system gas pressure.

essentially if the belts are on, the compressor is running and the fans in the car are running then the mechanical side is fine

From there you will need an aircon specialist to regas and test for leaks

If you have a pre 93 car the gas you need is now no longer available and the current gas will not run in your system, so you need to convert the system, expensive, or use a straight drop on gas which is less efficient

If you have a post 93 car you are ok for a few years until they ban that gas as well!!

Once you have tested for leaks, and there will be some, you need to replace the faulty parts, usually the condensor (expensive) and it will almost be a dead cert that all the O rings will have hardened and need replacing as well, aircon needs to be used to keep the seals subtle,

Once this is done take it back and have it filled and tested once more, not a cheap job, that's why you see so many old 40 and 300's advertised "aircon just needs a regas", in that case get it done it's 40 odd quid at my local place, what they really mean is "I've regassed it and it's all escaped and I can't afford to repair it"!! allow up to a grand for the work if you need parts, more if you have a V12 engine, the compressor on these is 400 quid alone, IF you can find one, V12 XJ40 condensors have been NLA for years now