64 11 224 Removing And Installing/Replacing Controller For Heater - A/C System Fan (Automatic A/C Basic)
WARNING: This page is about a different car, the 2008 BMW Alpina and 2007 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.
Replace controller for heater - A/C system fan. See 64 11 225 REPLACING CONTROLLER FOR HEATER - A/C SYSTEM FAN (AUTOMATIC A/C HIGH) .