Just paid $550 to have the timing belt (TJ Magna) done largely because in order to fix the oil leak the timing cover, sump and exhaust had to come off so may as well replace timing belt also whilst fixing the oil leak. But the air conditioner compressor won't work, the connections all seem OK, I am taking it back to the mechanic next week so they can look at it, they say they didn't touch it but the problem is that it worked fine before they worked on the car.

Could it be that they accidently let some gas out whilst lifting the engine to get the sump off and front exhaust manifold off?
Or is there something else I may have missed, the fuse relay under the bonnet seems OK.

I will find out when they have looked at it next week, glad it isn't the middle of summer, hope they don't charge me if it needs re-gassing, it had plenty of gas before. Will the compressor still kick in if it is low on gas?
If anyone else has experienced this after major work, let me know. Thanks in advance

Apparently the Air con compressor needs to be removed to get to the timing belt on the 3rd gens so maybe it wasn't fitted back in properly. Just take it back to them and let them know.

they may not have plugged the compressor in when they put it back together.

Yeah, I'll have to see what they say, I've had a look underneath and the wire connector is attached to the bottom of the compressor properly, I just hope they have not accidently discharged the gas and try denying it and say it was buggered anyway.

Cheers for the replies guys, have a good weekend.
P.S. Nemesis, you like Hall and Oates, I'm a keyboardist/Piano player, I play a lot of their stuff, they are very clever and were very popular in the 80's

Apparently they DO NOT HAVE TO TOUCH the aircon compressor when the belt is done, I have done hundreds of them and never touched the compressor.

To remove sump, same thing, does not need to be moved, nor for the exhaust manifold

The system has a switch which will disable it when the gas is low. Also check the plug as when it is disturbed sometimes the pins in the blug push back and do not make contact

Cheers Madmagna, the replacement of the "O" ring which seals between the oil pump and the engine block required sump removal, so I am assuming that there has been a lot of disturbance to everything located at the front and front bank of the engine and something has been bumped in the process.

I thought they had to remove the compressor in order to remove the drive pulley belts etc?
But then again that's probably where the belt tensioner comes into play.

I have checked and wriggled the wire plug connection underneath the A/C compressor but maybe I should pull it off completely and check the contacts.

UPDATE: A very nice sympathetic mechanic near my work had a look at it, it has plenty of gas and does not need re-charging, the switches and fans all work but he found a wiring break somewhere in the loom which supplies power to the A/C compressor, he thinks that the engine was jacked up to allow the removal and replacement of the front (right) engine mount and in the process a wire has been strained and pulled breaking the power supply but will require opening up the loom and tracing it.

He spent 30 minutes looking at it and didn't charge me even when I insisted, he is a great guy and I will now go to him from now on.

This is why I usually carry out my own mechanical work on my vehicles, I don't trust mechanics, they will lie and would eat a yard of **** rather than admit fault, when you find a good mechanic stick with them, it's like finding a good woman :)

But until I have fixed the problem and know what exactly is wrong it is unfair to blame the mechanic who did the timing belt, it could have been a bad connection which was accidently disturbed whilst fitting the timing belt and therefore could be bad luck, but the A/C was working when it went into his workshop and was not working when it came out.

Update: I found it, there was a plug on top of the A/C compressor which had not been plugged back together, could not see it without a mirror it was hidden underneath the alternator.

A simple mistake I know, but If the Mechanic had been bothered to at least have a proper look on the hoist or something when I mentioned afterward that the AC was not working he probably would have found it and I would not have spent a week finding it.

But he really wasn't very interested and seemed to just wish that I would just go away and never come back, well I will grant him that wish by never going back to him, interestingly he changed the oil but it looks like he kept the old oil filter so I have new oil but old filter WTF, I would not have minded paying another $10 for a new oil filter for a $550 timing belt job. Anyway Air cond works now, thanks for your replies everyone.