Ac problems?

Could also be underpressurized...On most AC systems, there is a under-pressure switch, which, as the name implies shuts off the system if there isn't sufficient pressure in the system. This prevents damage to your compressor...You might also check the overall system again and verify that you have an adequate charge of coolant in the system...The dye thing mentioned above is a good idea too...

One thing people almost always fail to mention in an a/c problem is the fact that atmosphere gets in the system when it gets low enough to go into a vacuum. If it was running in a vacuum you have to vacuum the atmosphere out of it or it will form ice crystals in the evaporator or the expansion valve, clogging the line. Just adding freon is not a good idea unless you know there is not any atmosphere in the system, leak or no leak!

Put UV dye in your ac (granted you know how- no different from a charge) and use a light to search for leaks. Sounds like you've just got a leak. The UV dye will glow under a black light or other UV reactive light. Where the dye glows is where the leak is (or in that vicinity). Could be something as simple as an o ring or line.

You have a leak! Have the system tested for leaks(usually the compressor seal). Is there a bit of oil spray around the compressor seal? Good luck! ;-)=