GM Service Manual Online
For 1990-2009 cars only

The front washer system consists of the following components:

    • A washer fluid reservoir that is shared with the rear wiper system
    • A washer pump that is attached to the washer fluid reservoir
    • Hoses
    • Nozzles
    • A washer switch

The washer fluid reservoir is mounted on the right fender behind the right headlamp. Actuate he front washer system by pulling the combination windshield wiper/washer lever rearward. The front washer will operate until you release the lever. When you activate the front washer system, the front wipers will operate at low speed regardless of the lever's position.

Intermittent wiper operation is achieved through the charging and discharging of the intermittent controller condenser. With the combination windshield wiper/washer lever in the INT position, the front wipers begin to operate at low speed. By the time the wiper motor makes one complete rotation, the condenser in the intermittent controller has discharged. Current flow to the wipers is then cut off until the condenser is recharged. This condenser recharges in approximately 6 seconds. When the wash switch is engaged while the intermittent wipers are activated, the wipers will begin to operate at low speed until the wash switch is released. When the switch is released, the wipers will resume intermittent operation.

Wiper/Washer: Pulse

Whenever the ignition switch is in the ON or the START position, battery voltage applies through the WIPER WASHER fuse to the front wiper/washer switch (in the combination switch) and to the front wiper motor pawl and switch contacts.

Washer Operation

When you pull the front wiper/washer switch forward, battery voltage applies through the wash switch contacts to the front washer pump. The front washer pump permanently grounds at G104 and operates as long as you hold the wash switch. In order to initiate wiper operation, battery voltage applies through the wash switch contacts and the intermittent controller to the OFF contacts of the front wiper/washer switch. This action applies battery voltage to the low side of the front wiper motor. The front wiper motor permanently grounds at G109 and continues to operate in low as long as you hold the wash switch in the ON position.

The front wiper motor pawl and the switch engage as the motor turns. The contacts remain closed until the wipers are in the park position. While the pawl and switch contacts are closed, voltage applies through the WIPER WASHER fuse, the front wiper motor pawl and switch contacts and the OFF contacts of the front wiper/washer switch to the low side of the front wiper motor. In this manner, the wipers complete at least 1 sweep after you release the wash switch.

Intermittent Operation

With the front wiper/washer switch in the INT position, the battery voltage applies through the WIPER WASHER fuse to the coil of an electronic relay in the intermittent controller and to a condenser also in the intermittent controller. The condenser charges to voltage and the relay energizes as soon as power applies. When the switch in the energized relay closes, current flows through the following components:

    • The YEL/BLU wire
    • The YEL/BLK wire
    • The front wiper switch and intermittent controller
    • The BLU wire to the front motor low side

The wipers begin to operate at low speed.

By the time the front wiper motor makes 1 complete sweep and the front wiper motor pawl and switch has engaged, the condenser in the intermittent controller discharges. This discharge in the condenser causes the intermittent controller relay coil to de-energize, and the switch in the relay to open. Current flow to the wipers is then cut off until the condenser recharges. In this manner, intermittent wiper operation is achieved through the charging and discharging of the intermittent controller condenser.

Low Operation

With the front wiper/washer switch in the LO position, battery voltage applies through the WIPER WASHER fuse, and the LO contacts of the front wiper/washer switch to the low side of the front wiper motor. Since the front wiper motor permanently grounds at G109, the motor operates at low speed as long as the switch remains in the LO position. When you place the switch in the OFF position, the pawl and switch assembly provides voltage to the motor until the wipers are in the park position.

High Operation

With the front wiper/washer switch in the HI position, battery voltage applies through the WIPER WASHER fuse, and the high contacts of the front wiper/washer switch to the high side of the front wiper motor. Since the front wiper motor permanently grounds at G109, the motor operates at high speed as long as the switch remains in the HI position. When you place the switch in the OFF position, the pawl and switch assembly provides voltage to the motor until the wipers are in the park position.