i have a 940se turbo and the air con hasnt worked since i bought it. i dont knw if im out of freon or not and im reluctant to get it filled just in case the problem is somewhere else and i waste my money. the compressor cant be heard kicking in but would it do that if it had no gas. not sure where to start looking any help would be appreciated

Maybe it's not a leak at all, but the common problem of a bad solder joint in the control unit in the dash.

Try disconnecting and jumpering the wires to the pressure switch on the receiver/dryer unit by the firewall. This will make your system think it has freon, and you should see the compressor clutch engage when you switch on the AC with the engine running.

It it does, your problem is lack of freon. Don't run the system until you get it charged. It may run for years on a charge.

If it doesn't come on, you have a control problem. This could be the MCC unit problem described in the FAQ. I takes an hour tops to remove/reinstall the unit, and about 10 minutes to fix if you can recognize and resolder a cracked solder joint.

Of course you could have both problems, it's a very real possibility. You fix the control unit, and you still need to jumper the switch to get the compressor to come on. Bummer, but at least the MCC was cheap to fix!

I'm not a big fan of the UV dye (just my opinion), if you've ever tried to inspect essentially a radiator with the dye you'll know what I mean. I've used the electronic sniffer(s) with good success and learned that the condenser on my 940 was leaking. I strongly recommnend, if you need to go this way, that you go OEM with the condenser.

A few of us here are in agreement that the 900 series has very decent output with the A/C functional. But we are also of the agreement that the A/C system is hard to KEEP functional. For whatever reason, the 900s seem to be like a lot of Volvos--hard to keep the A/C together.

There are a lot of potential leak points. You can spot the big ones with the naked eye. You can't see the little ones except with UV dye and a UV light.

The condenser is notorious; it often leaks at the top on the right hand side. Maybe there is some good reason, or maybe that's just where it's most likely to leak. Leaks could be originating from a host of other places, though.
--
Chris Herbst, near Chicago.

It's probably the condenser, but may be a the evaporator. the wisest approach is to take the car to a reputable volvo mechanic, and have them inject green dye and partially charge the system. This will tell you where the leaks are, and may offer some insight into the receiver/dryer, evaporator, condenser, and compressor. It will also be a fixed cost way to learn what the likely total cost will be. Give some thought to using a Nissens condenser, and definately get a variable orifice valve to replace the fixed one. Good luck.