Ignition positive voltage is supplied to the windshield wiper washer switch, windshield wiper motor relay, and the windshield wiper motor from the 30A WIPER fuse 9 in the fuse block. The windshield wiper motor relay is a transistorized solid state component which supplies voltage for windshield wiper motor operation during delay, mist, wash, and park modes.
LOW Speed Operation
When the windshield wiper washer switch is in the low position voltage is supplied from the switch through the low speed supply circuit to the windshield wiper motor. When the windshield wiper washer switch is moved to the off position a voltage signal is supplied from the position switch to the windshield wiper motor relay. The wiper motor relay supplies the wiper motor operating voltage until the position switch closes to ground indicating the windshield wipers are in the park position.
HIGH Speed Operation
When the windshield wiper washer switch is in the high position voltage is supplied from the switch through the high speed supply circuit to the windshield wiper motor. When the windshield wiper washer switch is moved to the off position a voltage signal is supplied from the position switch to the windshield wiper motor relay. The wiper motor relay supplies the wiper motor operating voltage until the position switch closes to ground indicating the windshield wipers are in the park position.
Delay Operation
When the windshield wiper washer switch is in the delay position voltage is supplied from the windshield wiper washer switch to the interval switch. The interval switch is a variable resistor and supplies the voltage signal to the windshield wiper motor relay which determines the frequency of the wiper cycles. The windshield wiper motor relay controls the wiper motor operation by supplying the motor operating voltage through the windshield wiper motor switch to the low speed supply circuit.
Mist Operation
When the windshield wiper washer lever is taped up and released a voltage signal is supplied through the delay signal circuit to the windshield wiper motor relay. The wiper motor relay starts a wipe cycle and continues supplying operating voltage to the wiper motor until the position switch signal closes to ground.
Washer Operation
When the windshield wiper washer switch is pulled to the wash position voltage is supplied from the windshield wiper washer switch to the windshield washer pump and the windshield wiper motor relay. The voltage supply from the washer switch to the washer pump is the operating voltage and is continuous as long as the washer switch is held closed. The voltage supply from the washer switch to the wiper motor relay is a signal voltage and the wiper motor relay will continue to supply the windshield wiper motor with operating voltage for approximately 5 seconds after the washer switch is released.
Windshield Washer Nozzle Operation
The heated windshield washer nozzles prevent nozzle freeze-up in cold weather. Ignition positive voltage is supplied to both of the windshield washer nozzles. The windshield washer nozzles are permanently grounded to G103.
