BMW E46 Heater Blower Resistor (Final Stage Resistor)
What is the E46 blower resistor and how do you recognise a fault?
The resistor (known in Finnish as the "hedgehog") is the heater blower's final stage resistor, which regulates the blower speed. When it fails, the low speeds stop working first, the blower wobbles, and finally it works only on full or not at all. It may also start by itself.
Does the resistor affect the temperature?
No. The resistor affects only the blower speed. If the heating is still lukewarm, the fault is elsewhere, for example a stuck water valve or a clogged heater core.
How do you replace the resistor on the E46?
1. Remove the glove box by removing six Phillips screws. 2. Press the two locks of the electrical connector and pull the connector off evenly. 3. Remove two Torx T20 screws, and the resistor comes off. A long extension makes it easier. The resistor is next to the blower in the footwell, behind the glove box. Behr or Hella was recommended as the manufacturer.