BMW DIY Video – Climate Control Blower Final Stage Unit (Blower Resistor), How To Replace
HEAT & A/C BLOWER HAVE A MIND OF ITS OWN?
* While this DIY is specifically addressing replacement of the blower final stage unit in the E53 X5 (01-06) models, the general procedures are applicable to the late E36 3-series (96-98/99), E46 3-series (98-05/06), E39 5-series (97-03), E85/86 Z4 (03-08) and E83 X3 (04-10). Specific details on the differences in trim panel removal are available in the applicable Bentley Publishers repair manuals.
One of the most common problems on later model BMWs is for the heat and A/C blower control to fail. This causes the blower motor to run at varying speeds or not at all, or even to run continuously (not shut off). Changing the blower speed input on the climate control panel may have intermittent or no effect on the actual blower speed or operation. The most typical cause for these symptoms is a faulty blower final stage unit (commonly known as the blower resistor).
Later model BMWs (generally from the late ‘90s-on, with digital climate control panels) use a continuously variable blower speed control as opposed to the earlier models that have three or four specific blower speeds that are chosen via a control knob or dial. This continuously variable control is accomplished through a digitally modulated “final stage unit”. These final stage units do eventually fail and as noted above, the common symptoms may include; blower motor will not change speed per the climate control inputs, blower motor changes speed on its own when not in “auto” mode, blower motor does not operate at all, blower motor will not shut off. If your BMW is experiencing any of these symptoms, it may need a new final stage unit.
Most BMW models have the blower final stage unit mounted in the area forward and above the left side of the passenger foot well (above and to the left of the passenger’s left foot). (PHOTO #7605-1) In this DIY we will be replacing the final stage unit in an E53 X5 (2000-06). The final stage location and the general procedures shown will be very similar for many BMW models, including; E36 3-series, E46 3-series, E39 5-series, E85/86 Z4 and E83 X3. The Bentley repair manuals detail the final stage unit location and replacement procedures for the different models.
12) Push down on the securing clip and pull the final stage unit out of the blower housing.
13) Insert the new final stage unit into the mounting hole. Align the two alignment pins with the two alignment ears on the unit. Press the unit in fully until the securing clip snaps over the edge of the final stage unit.
14) Finish installation by installing the final stage harness plug, footwell air duct, side console trim panel, glove box and forward under-dash trim panel.