Blower Motor FSR Failure

Blower Motor Final Stage Resistor (FSR) Failure

The FSR (also called the “hedgehog” due to its appearance) controls blower motor speed. It’s one of the most common electrical failures on the E46.

Symptoms

• Blower only works on highest speed
• Blower doesn’t work at all
• Blower speed doesn’t change with control adjustment
• Intermittent blower operation

Part Number

• FSR: 64 11 6 929 486

Replacement

The FSR is located in the HVAC housing under the dash on the passenger side:

1. Remove glove box or lower dash panel
2. Locate FSR connector (cylindrical unit with fins)
3. Disconnect electrical connector
4. Remove retaining screw(s)
5. Pull old FSR out
6. Install new FSR
7. Reconnect and test all blower speeds

Tips

• Aftermarket FSRs fail more frequently than OEM
• If FSR fails repeatedly, the blower motor itself may be drawing excessive current — replace blower motor