I have a 01 9-5 Saab. When the heater is first turned on when I star the car it works okay–the defroster and feet signal are on. But very quickly, the driver’s side is only getting cold air and the passenger’s side is getting blasted with heat. If I turn the heat up or down, it doesn’t make a difference. What could be wrong??
My first suspect is the control head,or course I have no data to back it up. It may be possible with a SAAB scan tool to manually command HVAC function or monitor outputs from certain inputs. After the head checks out you have the normal blend door, vacuum possibilites.
How expensive might this be to fix?