Wiper and Washer Systems: Description and Operation

In addition to the features of a conventional (non-pulse) Wiper System (mist, low and high speeds), the pulse-type Wiper/Washer System includes an operating mode in which the Wipers make single strokes with an adjustable time interval between strokes. The time interval is controlled by a Solid State Timer in the Wiper Motor Module. The duration of the delay interval is determined by the Pulse Delay Resistor in the Wiper/Washer Switch Assembly.

PULSE OPERATION

With the Wiper/Washer Switch in "PULSE," battery voltage is applied to the Wiper Motor Module at terminal "B", on connector C2, through the LT BLU wire. Voltage is also applied to terminal "A", on connector C1, through the BRN wire and the Pulse Delay Resistor in the Wiper/Washer Switch Assembly. The battery voltage at terminal "B" energizes the Park Relay, which closes its contacts. In response to the voltage at terminal "A", the Solid State Timer momentarily closes contact "A" on the Control Board which applies the battery voltage at terminal "B" to the contacts of the Park Relay, starting the Wiper Motor.

A second mechanical arm (end of sweep input) operates contacts on the Control Board which cause contact "A" to open when the Wipers have completed their sweep. Since the Park Relay remains energized, the Wipers do not park but remain just above the parked position until the Control Board closes contact "A" again to start another sweep.

LOW SPEED

In the "LO" position of the Wiper/Washer Switch, battery voltage is applied at terminals "C" and "B" on connector C2 of the Wiper Motor Module through the LT BLU and GRY wires. The Park Relay is again energized and battery voltage is applied to the Park Relay contacts from terminal "C" and the Wiper Motor, which runs continuously.


HIGH SPEED

With the Wiper Switch in the "HI" position, battery voltage is supplied directly to the Wiper Motor, without passing through the Park Relay contacts. The input (PPL) wire is connected to a separate armature brush for high speed operation.

When turned "OFF" from "HI," the Wipers complete the last sweep and park. To do this, the Wiper Motor receives battery voltage in the "OFF" position of the Wiper Switch. This voltage is applied through the GRY wire to terminal "C" of connector C2. The Park Relay is de-energized when the Wiper/Washer Switch is moved to "OFF," but the contacts remain closed until the Wipers reach the "PARK" position.

The Wiper Motor is protected by a circuit breaker. If the Wipers are obstructed, by snow or ice for example, the additional current drawn by the Wiper Motor will cause the circuit breaker to open the circuit. The circuit breaker resets automatically when it cools.

WASHER

When the Washer Switch is held "ON," battery voltage is applied to the Control Board through the BRN and LT BLU wires. The Park Relay is energized by the battery voltage at terminal "B" on connector C2. The Control Board turns "ON" the Washer and Wiper Motors by closing contacts "A" and "B". If the Washer Switch is held "ON" for less than one second, the Control Board Circuit turns on the Washer Motor for approximately 2+ seconds. The Control Board turns the Wiper Motor "OFF" approximately 6 seconds after it interrupts power to the Washer Motor. If the Wipers had been in "PULSE," "LO" or "HI," they would return to that operation after the wash cycle.

If the Washer Switch is held "ON" for more than 1 second, the voltage on the BRN wire causes the Control Board to keep the Washer Motor "ON" only as long as the Washer Switch is held. The Wipers also come "ON" at low speed and continue for approximately 6 seconds after the Washer Switch is released. They then return to the "PARK" position.

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 low speed.