Washer System
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The windshield washer and the rear window washer are activated by the internal wiper motor modules when they receive a ground from the multifunction switch between the washer inputs. Depending on the correct ground, the internal wiper motor modules activate either the windshield washer or rear window washer relays (internal) by grounding the respective relay coil. When either relay is activated, it connects voltage to the washer pump while the deactivated relay provides ground to the washer pump. In this manner, voltage polarity is reversible to achieve directional change of the washer pump and washer fluid.