BMW E34 heater blower not working or working only at full speed
Why does the E34 blower work only at full speed or only at a few speeds?
The most common cause is the blower series resistor, which is located in the front passenger footwell. If the speed control does not work but the temperature control does, the fault is here. The resistor may be bent or have come loose from its riveting. After a long seizure, replacing the resistor may help only briefly.
The blower does not blow at all - where is the fault?
First check the blower fuse: according to the wiring diagram, number 19 is 30 A. If a smaller fuse is fitted, it can blow and heating and ventilation stop. If smoke comes from the blower, the series resistor may have burnt and melted the housing; then the resistor must be replaced.
The blower squeaks or rattles - how is it fixed?
Usually the blower bearing is broken and the blower is replaced; the fan blades can be moved from the old motor to the new one. The blower is reached from the engine bay side through the bulkhead hatch, which is held by five screws behind the engine.