Rear Wiper/Washer System

PULSE REAR WIPER/WASHER

Voltage to the Rear Wiper/Washer is supplied through the ACC-IGN circuit breaker and WHT (393) wire with the Ignition Switch in ACC or RUN.

WIPERS

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 wipers make 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 LO position, the Wiper/Washer Switch supplies voltage to the GRA (391) wire and the Pulse/Speed/Wash Control. 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 at low speed until they are turned off.

With the Wiper/Washer Switch in the HI position, battery voltage is supplied from the DK GRN (392) wire directly to a second armature terminal of the Wiper Motor. The wipers run at high speed. When the Wiper/Washer Switch is turned to OFF, the wipers complete the last sweep at low speed and park.

When the wipers are turned off, the Wiper Motor runs at low speed until the wiper blades reach the PARK position. At that time the Park/Run Relay opens and shunts the Wiper Motor to stop it immediately. The wiper blades remain in the PARK position.

When the control 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 low speed.

With the Wiper/Washer Switch in PULSE, voltage is supplied to the GRA (391) wire, the Wiper Motor Module and the Solid-State Control Board. 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 the LT BLU (97) wire 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 blades have reached PARK, the Park/Run Switch opens, deenergizing the Park/Run Relay. The wiper blades remain 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 resistors. The delay can be adjusted from 0 to 43 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 the DK GRN (392) wire. 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 six 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.