Seats are always heated
A common problem in the Saab 9-5 is that the seat heaters are always on. The equally common cause of the problem is that the slider for adjusting the seat heating is broken inside. If you have one working slider and one malfunctioning you can try switching places to pinpoint the fault.
A used set of sliders costs about $20 and is easily replaced. Just pull the old one out and insert the new one.