Saab 9000 cabin fan sensor

ACC Cabin Fan Sensor failures can often be identified by noting that noise begins to come from the small motor in the dash.  Eventually the climate control will only work on full hot or full cold. That fan runs when the ventilation system is running and when it fails usually begins to squeal. Replacement of the Fan sensor is the only cure. It can be removed in most cases by pushing it from the rear. You can often access the rear by going through the radio slot or the ashtray.

This is a good used unit, that still runs quiet!  Should last you for several years.