Air conditioning/heater stops blowing air after a while
 

Hello,

I was driving for about half an hour to an hour today and had the AC turned on. After a while the AC stopped blowing air. So, I thought there might be a problem with the AC unit. I turned up the temperature to heat and still no air. I could hear the AC unit working/ humming at least but no air. After parking the car and then checking it after nearly 3 hours, I returned back to my car and it started functioning properly.

Has anyone experienced this problem with blowing air after prolonged use of AC/Heater? Hopefully it's nothing serious. Do I need to play around with any settings? or check something else before I take it to the mechanic?

Please advise.
Thanks in advance.

1999 C2 911