Washer System
WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The windshield washer is activated by the internal wiper motor module when it receives a ground from the multifunction switch between the washer inputs. Dependent on the correct ground, the internal wiper motor module activates the windshield washer relay (internal) by grounding the relay coil. When the 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.