The most common causes for AC fan blower motor not working in BMW 3 Series are blown fuse, bad relay, resistor or control module malfunction and faulty blower motor. However, a bad electrical connector or broken wire, or a defect in the climate control unit can also cause the blower motor to stop working. 1. Mar 26, 2013. #4. Generally if the module is a resistor, there is one position where the. motor is fed directly. So when the resistor goes open, your only speed. is full blast or off. If you have more speed values than could be explained by taps in a. resistor, then you have an electronic control of some flavor. Reasons a 1991 Ford E-350 Econoline Heater Isn't Working. 1991 Ford E-350 Econoline. The most common reasons a 1991 Ford E-350 Econoline heater isn't working are a broken heater blower motor, a problem with the thermostat, or a failed heater blower motor resistor. 0 %. 31 % of the time it's the. The best most complete guide to replacing that failed or squeaky blower motor on your X, enjoy, like and subscribe. Feel free to leave a comment or question If the blower fan fails to blow air when the A/C or heater is turned on, the problem may be a defective control switch, control module (or control head depending on how the system is wired), resistor block, blower motor, relay or fuse. The blower obviously can’t operate if it isn’t receiving any voltage. 1. Weak Airflow from the Vents. This is usually the first indication that you may have a faulty blower motor. If the airflow coming out of the vents is weak, check the motor. It can mean that your furnace blower motor is having a hard time pushing enough air through the ducts to achieve your desired temperature. The best-selling BMW 3 Series is the 328i base model. The three top problems with this affordable BMW car are as follows: Oil leaks from the lower engine area — reported by over 200 owners. Blower final stage fan resistor failure — reported by more than 100 owners. Outside mirror folding out too far — reported by over 80 owners. BMW e39 FSU Unit Replacement TutorialIn this video i show you how to replace / repair the BMW 5 series heater / blower fan resistor, or as BMW call it final 7anIR.