Hmmmmm....sounds like a secret service bulletin since there are about 6 things that could be at issue:
1) AC Condensor
2) IMA interface to AC
3) Engine interface to AC
4) AC Controller in the car
5) Thermostat (sensor) of AC controller in the car
6) AC on/off switch
We know the fan works so we can eliminate that it is not blowing....
FYI, AC should always be run periodically, even if it's not necessary. The system will last much longer. Plus you'll find out if it's on the fritz much sooner