Circuit/System Description
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The rear window washer pump is controlled by the rear window wiper washer switch through the rear washer pump relay. The switch supply voltage is from the body control module (BCM), and when the WASH switch is pressed battery voltage is applied to the rear washer relay control circuit and to the rear wiper switch signal circuit. When the rear wiper motor module receives battery voltage on the rear wiper switch signal circuit, the wiper motor will operate continuously for as long as the voltage is present and several cycles after the switch is released. The rear washer relay control circuit is used to energize the relay coil and close the rear washer pump control circuit to battery voltage.