Blower Motor Switch
WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
The blower motor switch is mounted in the HVAC module and controls blower motor speed by adding or bypassing resistors in the blower motor resistor in all modes except OFF.