Wiper and Washer Systems: Description and Operation

The Wiper Motor is protected by a Circuit Breaker. If the Wipers are blocked (by snow or ice for example) the Circuit Breaker will open the circuit. The Circuit Breaker resets automatically when it cools.

Delay Operation
With the Wiper/Washer Switch in "DELAY," battery voltage is applied to the Wiper Motor C1 through CKT 91. Voltage is also applied through CKT 94, and the pulse delay resistors in the Wiper/Washer Switch. The battery voltage at CKT 91 energizes the Park Switch Coil, which closes its contacts. In response to the voltage at CKT 94 the Solid State Timer momentarily closes contact A on the Cover Assembly which applies battery voltage of CKT 91 to the contacts of the Park Switch, starting the Wiper Motor.

A mechanical arm (end of sweep input) operates contacts on the Cover Assembly, which causes contact A to open when the Wipers have completed their sweep. Since the Park Switch Coil remains energized, the Wipers do not park but remain just above the "PARK" position until the Cover Assembly closes contact A again to start another sweep.

The length of delay time between sweeps is controlled by the delay resistors. The delay is adjustable from 0 to 25 seconds.

Low Speed
With the Wiper/Washer Switch in "LO," battery voltage is applied at the Wiper Motor connector C1, through CKT 91 and CKT 95. The Park Switch Coil is again energized and battery voltage is applied to the Park Switch contacts and the Wiper Motor, which runs continuously.

High Speed
With the Wiper/Washer Switch in the "HI" position, battery voltage is applied directly to the Wiper Motor, connector C2, CKT 92, without passing through the Park Switch contacts CKT 92 is connected to a separate Wiper Motor brush for high speed operation. The Park Switch coil remains energized in the "HI" position because of the voltage that is present at the low speed Wiper Motor brush when voltage is applied to the high speed brush. The current path from the low speed brush to the Park Switch coil is completed through the Wiper/Washer Switch. An open in this circuit will cause the wipers to cycle in and out of Park in "HI" and possible prevent "LO" speed operation.

When turned off from "HI," the wipers complete the last sweep at low speed and park. To do this, the Wiper Motor receives voltage in the "OFF" position of the Wiper/Washer Switch, which is applied through CKT 95 of connector C1. The Park Switch is de-energized when the Wiper Switch is moved to "OFF," but the contacts remain closed until the wipers reach the "PARK" position.

Washer
When the Wiper/Washer Switch is held "ON," battery voltage is applied to the Cover Assembly through CKT 94 and CKT 91. The Park Switch is energized by the battery voltage of connector C1, CKT 91. The Cover Assembly turns on the Washer and Wiper Motors by closing contacts A and B. The Cover Assembly turns the Wiper Motor OFF approximately 6 seconds after it interrupts power to the Washer Motor. If the Wipers had been in "DELAY," "LO" or "HI," they would return to that operation after the wash cycle.

Mist
When the Wiper/Washer Switch is moved to "MIST" and released, the wipers make one sweep at low speed and return to "PARK." The circuit operation is the same as that of "LO."