Circuit Operation

PULSE REAR WIPER/WASHER
Voltage to the Rear Wiper/Washer is supplied through the CKT 393 with the Ignition Switch in ACC or RUN.

WIPER
In addition to the features of a conventional (non-pulse) Wiper System (MIST, LO and HI speeds), the Rear Pulse Wiper/Washer System includes an operating mode in which the wiper makes single strokes with an adjustable time interval between strokes. The time interval is controlled by a Solid-State Pulse/Speed/Wash Control in the Wiper Motor Module. The duration of the relay interval is determined by the Pulse Delay Resistance in the Wiper/Washer Switch.

In the ON position, the Wiper/Washer Switch supplies Voltage to the Pulse/Speed/Wash Control through CKT 391. The Pulse/Speed/Wash Control provides ground to the Park/Run Relay which is energized and supplies Voltage to the brushes of the Wiper Motor. The wipers run until they are turned off.

When the wiper is turned off, the Wiper Motor runs at low speed until the wiper blade reaches the PARK position. At that time the Park/Run Relay opens and shunts the Wiper Motor to stop it immediately. The wiper blade remains in the PARK position.

With the Wiper/Washer Switch in PULSE, voltage is supplied to the Wiper Motor Module through CKT 391. Voltage is supplied to the Park/Run Relay coil which is momentarily grounded by the Pulse/speed/Wash Control circuit and the relay closes. Battery voltage is supplied by CKT 97 through the closed contacts of the relay to run the Wiper Motor at LO speed. The relay remains energized as long as the contacts of the Park/Run Switch remain closed. When the wiper blade reaches PARK, the Park/Run Switch opens, de-energizing the Park/Run Relay. The wiper blade remains in PARK until the Control Board grounds the Park/Relay coil to start another sweep. The delay time between sweeps is controlled by the pulse delay resistor. The delay is approximately 9 seconds.


WASHER
When the Washer Switch is depressed, voltage is supplied to the Solid-State Control Board in the Wiper Control Module. The Wiper Switch supplies battery voltage to the Washer Motor through CKT 392. It also starts the wiper cycle through the low speed brushes of the Wiper Motor. The washer continues to run as long as the switch is held down. The Solid-State Control Board keeps the wipers on for approximately six seconds after the washer goes off. If the washer is switched on during the PULSE operation, the wipers run in low speed for 6 seconds. When the wash cycle is completed the Wipers return to the pulse operation.

The Wiper Motor is equipped with a Circuit Breaker which protects the motor when the wipers are blocked. The resulting high current will open the Circuit Breaker which will reset upon cooling.