I am not a mechanic, but had the same problem with my '95 silverado. The problem was a rod or arm had come disconnected from a lever under the dash at the actuator. The actuator was on the end of the heat/air unit by the gas pedal. I removed the bottom trim panel on the dash to make it easier to get to, but not sure this was necessary. Found the rod was loose from the lever that connects to a door internally that directs the air flow. Just reconnected and has stayed connected so far about four weeks ago.
Wednesday, December 17th, 2008 AT 8:31 AM