Multifunction Switch

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For multifunction switch concerns, refer to one of the following articles:

For exterior lighting, refer to EXTERIOR LIGHTING article.
For wipers and washers, refer to WIPERS AND WASHERS article.

The multifunction switch controls the various components (high beam headlamps, flash-to-pass, turn signal and windshield wiper) by grounding certain Lighting Control Module (LCM) circuits and wiper motor circuits. When the LCM detects the specific ground, it sends a voltage to the appropriate component to activate it. The LCM controls the high beam headlamps and the flash-to-pass. The turn signals are controlled directly by the multifunction switch. The high beam headlamp and the turn signal portion are normally open switches that close when activated. The flash-to-pass switch is a momentary contact switch that grounds the LCM high beam headlamp circuit. The windshield wipe and wash functions are controlled directly by the multifunction switch, wiper and washer motor.