Not sure about your car. But with the AC on and the car running you should see the aux fan kick on, it's almost impossible to hear from inside the car. Need to get out and look. Make sure the fan is not running, if so sounds like you found problem. Now you need to find root cause. Fan it's self (don't crap out too often). Fuse, sensor, etc. I am not the greatest at electrical diagnosis. Do a search on the subject, no doubt these guys have already addressed this issue.

Joel