Air conditioning cut out suddenly on 02 jetta tdi

So yesterday my air condition cut out and would only blow very hot air, when i turned off the air conditioning and just put it on fan it still only blew very hot air. The same thing happened when i put the recirculation on. Does anybody have any idea of what could have possibly went wrong? It was a pretty hot day so my first guess was just to check the fuse, but it wasn't blown. Any advice is greatly appreciated, thank you.d

Have you tried checking the cooling fans? You can do this by turning your key to ON without the engine running and pushing the a/c button, both fans should turn on. There is a thread on how to do this here: http://forums.tdiclub.com/showthread.php?t=242699

Also check to make sure the a/c compressor clutch is engaging when you have the system switched on, if it doesn't run the system may not have enough freon to operate.