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Cabin blower does not work or works only on maximum speed

Q: What are the symptoms of Cabin blower does not work or works only on maximum speed in BMW 3 Series (E46)?

Irregular A/C operation. No blowing from vents. Blower works only on highest speed

Q: How to fix Cabin blower does not work or works only on maximum speed in BMW 3 Series (E46)?

Replacing the blower end resistor (Hedgehog). Repair possible in 45 minutes behind the passenger glove compartment.

in BMW 3 Series (E46) (1998-2011)

Symptoms

Irregular A/C operation
No blowing from vents
Blower works only on highest speed

DTC error codes

No codes

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Technical diagnosis (Premium)

Recognized technical fault:

Auxiliary controller voltage instability detected

Technical analysis

Detailed analysis of HVAC controller operation parameters, CAN bus data readings, and diagnostic signal waveforms. Purchase PRO access or log in to read the full fault analysis.

Confirmed solution

Complete step-by-step repair procedure including module non-volatile memory reset, sensor calibration, and correct wiring routing. Unlock the full report to see the instruction.

Parts needed

Filters ferrite anti-interference / noise suppressor
Auxiliary starting battery (depending on cell status)

Workshop hacks

Important workshop tips for mechanics regarding bypasses without expensive control module replacement and manufacturer software service bulletins.

TSB / TPI service bulletins

TSB-24-HVAC-01TPI-2068943/2

A/C Technical Specifications

(F34) Gran Turismo

Refrigerant: R134a Amount (g): 550g Oil: PAG PAO 68 lub PAG ISO 46 b.d. Oil (ml): b.d.ml

(F30) Hybrid 3

Refrigerant: R134a Amount (g): 740g Oil: PAG PAO 68 lub PAG ISO 46 b.d. Oil (ml): b.d.ml

(F30/F31)

Refrigerant: R134a Amount (g): 550g Oil: PAG PAO 68 lub PAG ISO 46 b.d. Oil (ml): b.d.ml

See full specification

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