Windshield Wiper Operation
WARNING: This page is about a different car, the 2013 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The wiper relay is activated whenever the ignition is in the ON position. The wiper relay provides voltage to the windshield wiper motor.
The wiper system is activated by the wiper/washer switch. The SCCM commands the windshield wiper motor to activate the appropriate wash, low, high and intermittent modes through a private LIN .
When the wiper/washer switch is in the HIGH position, the windshield wiper motor also receives a ground signal which is hardwired directly from the SCCM (bypassing the logic within the module). This fail-safe circuit makes sure that the windshield wipers function in HIGH speed mode in the event of a LIN communication failure.