BMW E36 heater blower works only at certain speeds
Why does the E36 blower work only at certain speeds?
The most common cause is a fault in the blower series resistor. In a car with automatic climate control the blower does not work at speeds 1–3, only at 4. Without automatic climate control the blower may run at full power when the resistor is broken. A worn speed switch can also leave a speed from engaging.
Where is the E36 blower series resistor and how is it replaced?
The resistor, also called the hedgehog, is in the driver's footwell behind the centre console, held by two torx screws. Without air conditioning it is on the passenger side behind the glovebox; the glovebox and the lower cardboard panel are removed, and the resistor is held by plastic tabs. The thermal fuse of the resistor often blows first.
Why does the E36 blower not work at any speed or cut in and out?
The cause can be the series resistor or the blower motor. The carbon brush wire of the motor can wear through or the motor can wear out. The motor is on the engine bay side under the windscreen; for removal the wipers are moved to the middle of the glass.