Low-Speed Windshield Wipers
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
Low speed is activated when the multi-function switch supplies a specific ground to the speed inputs of the windshield wiper motor module. The windshield wiper motor module then supplies ground to only the windshield wiper run/park relay coil, activating it. When the windshield wiper run/park relay is activated, the deactivated high/low relay connects voltage to the windshield wiper motor low input activating the wiper motor. The windshield wiper motor module continues to operate the windshield wiper motor in the same manner as in high speed, but in low speed with the wiper motor connected to the low-speed input.