BMW Questions? Ask a BMW Repair Expert for Answers.
1. The climate control blower motor is controlled by a final stage unit which receives variable voltage from the climate control head. 2. Disconnect final stage unit which is located beneath passenger side of dash and installed near firewall into the lower side of the heater box. Check for variable voltage coming from climate control head when fan setting is changed on the Blue/Red wire. If voltage does not change as fan speed is changed at the control head, wiring or control head problem may exist. 3. A Yellow/Green wire should have power from fuse 50. 4. The Brown wire is direct to ground. 5. The Black/Green and Red/Green wires go directly to the blower motor. Supply them with power on one wire and ground on the other and the blower motor should operate. 6. If voltage from control head varies when changing blower speed, but blower will not operate at the correct requested speed and/or operates independent of the request, the final stage unit should be replaced
Final stage appears to be screwed into heater case, but is actually held by a large clip which can be pressed and the final stage can be removed at the same time. The blower motor is located under the center of the dash. The top part of the dash needs to be removed in order to replace the blower motor.