High-Speed Windshield Wipers

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

When the multifunction switch is set to the HIGH-speed position, it supplies ground to the high/low-speed relay coil and the run/park relay coil, which causes the windshield wiper motor to operate at high speed. During HIGH-speed operation only, both the high/low-speed relay coil ground and the run/park relay coil ground are controlled directly by the multifunction switch. This differs from LOW-speed or INTERMITTENT operation when the run/park relay coil is controlled by the microprocessor. When the switch is placed in the OFF position, the motor continues to operate until the motor returns to the PARK position and the internal Hall-effect sensor senses the motor magnet. The output to the run/park relay deactivates the relay and disconnects the voltage to the motor.

Since the high/low relay coil and the run/park relay coil are both controlled by a hard-wired circuit to the multifunction switch, the windshield wipers will still operate in high-speed mode if the internal windshield wiper module fails, but will not automatically park when the multifunction switch is turned to the OFF position.