This video shows you how to replace the Blower Motor (Blower Fan) Resistor that controls the operation of the cabin fan. The video is specific to the Saab 9-3 model year 2004 and later that have the manual climate control in the car dashboard. Unfortunately, this is a common problem. When the resistor (which is a solid stated fan control) fails it often fails in a manner that provides continuous power to the cabin fan, even when the key fob is removed from the ignition. This causes the battery to drain if you do not notice that the cabin fan is running after you turn off and leave the vehicle.
The problem may also be caused by faulty cabin fan that is drawing too much power, for example due to water getting to the fan and impairing the spinning of the fan. A higher power draw would cause the resistor to overheat and fail. If that is the case, you need to replace both the blower motor resistor control and the cabin fan and determine how the water got to the fan.
Also, when the fan control resistor fails, it may overheat and melt / fuse the plastic of the resistor cable connector to the plastic mail connector part of the resistor. You can observe that also in this video.
The part number and other identifiers on the resistor on the car in the video were:
Behr 65922
Delphi 52488536
GM 90566802 (the EPC part number is 90566802 but it has been superseded by 90512510)
Valeo 539 9960.010
Sitronic 17070404