While driving home from work today my 97 f250 made a wooing of air sound behind the glove box in the dashboard. It really sounded like you was filling the lumbar with the button on the driver seat bit it was coming from the glove box area. It did it 2 times just for less than 5 seconds each time. Any idea?

 

Just a WAG, the vacuum line for the heater control. One may be loose.