Saturn Repair Problems? Ask a Mechanic for Answers ASAP
From what you are describing here, it sounds like there is a problem with the Air Temp Actuator. This actuator is what turns the door internal of the HVAC housing to switch between heat and A/C as commanded by the control panel. The Actuator is mounted to the side of the HVAC housing, behind the glove compartment (click here for image). To gain access, the glove compartment will need to be removed. Inspect the electrical connector and wire harness for any loose, broken or damaged wires or any signs or water intrusion. If the visual inspection checks ok, remove the actuator and turn the door pin by hand. If the temp still does not change, the HVAC housing will need to be removed, opened and the internal door repaired as needed. If the temp changes, replace the Air Temp Actuator. If my answer has helped you, please help me by leaving a rating using the stars at the top of this page or accept the answer so I may be credited. If you cannot rate or do not see the rating stars, please let me know. You can ask follow-up questions after you rate.