Windshield Wiper Operation
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The multifunction switch is mounted to the Steering Column Control Module (SCCM). The SCCM commands the windshield wiper motor to activate the appropriate wash, low, high and intermittent modes through a private Local Interconnect Network (LIN).
When the multifunction switch is in the HIGH position, the windshield wiper motor also receives a ground signal which is hardwired directly through the SCCM (bypassing the logic within the module). This fail-safe circuit makes sure that the windshield wipers will function in HIGH speed mode in the event of a LIN communication failure.