Blower Control Knob (Rear Mounted)
WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.
Switch operates auxiliary blower motor at 4 different speeds: low, medium-low, medium-high, and high. See Fig 1. Auxiliary system blower speed can be controlled by knob only when front-mounted auxiliary system blower control lever (on front climate control panel) is in REAR position.