Are you quite sure you've actually got the A/C turned on..(i.e. button pushed in w/green light.?) Sounds like your just blowing air, especially if you don't feel or hear the compressor kicking in....
If this is all O.K., I'd drive to a service advisor at the local Volco dealer., play dumb and ask then to show you...I've done this a couple of times when I first purchased my S80...They always like to feel superior to the average layman.
Good luck...

 

It could be your system is low on refrigerant and is tripping the low sensor, which will prevent the A/C compressor clutch from engaging. As the A/C system is a closed system, if you are low, you probably have a leak.

Leaks tend to rear their ugly head as you move from the winter months to the spring. The winter months cause the rubber connectors to shrink, normally this is not an issue, but as the rubber becomes aged, they don't seal as well and thus leaks start. Also, with time some of the lines and connections, corrosion starts to set in and they too will begin to leak.

Although not the most environmentally friendly way to test to see if this is a problem, go purchase some refrigerant at any auto store (ie. Autozone) with the connecting hose/gauge. Avoid refrigerants with sealants or oil added, they can cause more problems then they are worth and adding too much oil is bad for the system.

Connect the hose to the refrigerant can and to the low pressure service port (accessed in the engine compartment, usually towards the passenger side near the drive belts). Turn the car on and turn the A/C on to maximum. Check the pressure on the gauge (part of the hose/gauge). If the gauge doesn't register or reads low, shake the can of refrigerant and depress the trigger on the hose to start refilling the system. You may start to hear the compressor kick on and off, this is a good sign, although it may still not be enough to cool your car.

If the above works, it means you have a leak, continue to fill the system further and see if it holds the refrigerant. Depending on where the leak is, it may hold for the rest of the year, or if it is a larger leak or the start of one (corrosion issue) then it may leak back out in a very short time.

In the end, you really should take it to a shop and have them add some dye to the system and locate the leak, but understand, HVAC work is expensive, so don't expect to walk away with a bill less then a few hundred dollars, so I can also respect the fact that the above is a valid way to do some testing/fixing yourself.