Windshield Wiper/Washer System Operation

The windshield wiper motor module is part of the windshield wiper motor cover and controls wiper motor operation. The windshield wiper motor is a 2 speed motor and is operated at low speed in all modes except HIGH. The accessory voltage supply circuit to the windshield wiper motor provides the power for operating the wiper motor and the wiper motor module. The windshield wiper switch supply voltage circuit is a 12-volt reference from the wiper motor module to the wiper/washer switch. The WASH, MIST, LOW, and DELAY modes are controlled by the windshield wiper/washer switch through a series of internal resistors, and the switch position determines the point on the resistor assembly where the reference voltage is applied. The windshield wiper switch signal circuit supplies the signal voltage from the switch assembly to the wiper motor module which determines the operating mode. Windshield wiper motor high speed operation is controlled by the windshield wiper/washer switch through the windshield wiper switch high speed signal circuit. The windshield wiper switch high speed signal circuit is supplied 12 volts by the wiper motor module and when the wiper/washer switch is turned to the HIGH position the windshield wiper switch high speed signal circuit is grounded.

The washer fluid pump is a reversible motor and is used to wash both the windshield and rear window. The washer fluid pump is controlled by the windshield wiper motor module through the washer fluid pump relay. The washer fluid pump relay coil and switch are supplied battery positive voltage, and during the windshield or rear window wash modes the wiper motor module grounds the washer fluid pump relay control circuit energizing the relay. When the relay is energized battery positive voltage to the switch side of the relay is supplied to the windshield wiper motor module through the washer fluid pump supply voltage circuit. The windshield wiper motor module also controls the voltage polarity of the washer fluid pump control circuits. During windshield wash operation the windshield washer pump control circuit supplies positive voltage to the washer fluid pump and the rear window washer pump control circuit is the ground circuit.