Wiper/Washer System Circuit Description (Standard)

Wiper/Washer System Circuit Description (Standard)

With the ignition switch in the ACC position or the RUN position, voltage is available to the wipers and washers through the WASH/WIPE fuse and CKT 143 (YEL).

When the wiper/washer switch is in the LOW position, battery voltage is supplied through the CKT 112 (GRY) directly to the low speed brushes of the windshield wiper motor. The windshield wiper motor runs at low speed.

When the windshield wiper switch is in the HIGH position, battery voltage is supplied through CKT 92 (PPL) to the high speed brushes of the windshield wiper motor. The windshield wiper motor operates at high speed.

The park switch is open only when the wiper blades are in the PARK position. In all other positions, the park switch is closed. When the windshield wiper switch is moved to OFF, battery voltage at CKT 143 (YEL) is supplied through the park switch, CKT 196 (YEL), the windshield wiper switch, and CKT 91 (GRY) to the low speed brushes of the windshield wiper motor. The windshield wiper motor continues to run at a low speed until the wiper blades reach the PARK position. At that time, the park switch opens and stops the windshield wiper motor.

The windshield wiper motor is protected by a circuit breaker which opens if the current through the motor rises to a high level. This may happen if the wiper blades are blocked by ice or snow. The circuit breaker resets automatically after it cools off.

Low Speed

In the LOW position, the windshield wiper switch supplies voltage to CKT 112 (GRY) and the wash control. The wash control provides ground to the park/run relay (internal to windshield wiper motor) which is energized and supplies voltage to the brushes of the windshield wiper motor. The wipers run at a low speed until they are turned off.

High Speed

With the windshield wiper switch in the HIGH position, battery voltage is supplied from CKT 92 (PPL) directly to a second armature terminal of the windshield wiper motor. The wipers run at high speed. When the windshield wiper switch is turned to the OFF position, the wipers complete the last sweep at low speed and park.

Park

When the wipers are turned off, the windshield wiper motor runs at low speed until the wiper blades reach the PARK position. At the same time the park/run relay (internal to the windshield wiper motor) opens, stopping the windshield wiper motor immediately. The wiper blades remain in the PARK position.

Washer

The washer motor is energized whenever the windshield washer switch is pressed and runs as long as the washer switch is closed. Battery voltage is supplied through the windshield washer switch and CKT 228 (RED) to the windshield washer pump. The other terminal of the windshield washer pump is grounded through CKT 150 (BLK).