Wiper and Washer Systems: Description and Operation

WINDSHIELD WIPER SYSTEM

WARNING: ON VEHICLES EQUIPPED WITH AIRBAG, REFER TO PASSIVE RESTRAINTS FOR SAFETY PRECAUTIONS. DISCONNECT THE NEGATIVE CABLE FROM THE BATTERY BEFORE SERVICING COMPONENTS INVOLVING THE AIRBAG SYSTEM. ACCIDENTAL DEPLOYMENT OF AIR BAG AND PERSONAL INJURY CAN RESULT.

DESCRIPTION
Front
The front wiper system provide the driver with normal wipe (low and high speeds), intermittent wipe, wipe after wash, and pulse wipe functions. The driver selects the wiper function via a resistive multiplexed stalk switch mounted on the steering column. When the wiper is in the ON position and the ignition is turned OFF, the wiper will continue to run until it reaches its PARK position.

Other front wiper system features:

Speed Sensitive Intermittent Wipe Mode
There are 6 individual delay times with minimum delay of 1/2 second to a maximum of 18 seconds. When the vehicle speed is under 10 MPH, the delay time is doubled to provide a range time of from 1 second to 36 seconds.

Pulse Wipe
When the wiper is in the off position and the driver presses the wash button for more than 62 msec but less than 1/2 second, 1 wipe cycle in low speed mode will be provided.

Wipe After Wash Mode
When the driver presses the wash button for over 1/2 second and then releases it, the wiper will continue to run for 2 additional wipe cycles.

Rear
The rear wiper system provides the driver with continuous, intermittent, and wiper after wash functions. The driver selects the wiper function via a resistive multiplexed switch mounted in the HVAC control.

OPERATION
The windshield wipers can be operated with the windshield wiper switch when the ignition switch is in the RUN or ACCESSORY positions. The windshield wiper system is protected by a 40 amp fuse (9) located in the Power Distribution Center (PDC) in the engine compartment. The windshield washer circuit is protected by a 6 amp fuse (9) located in the Junction Block. The wiper motor has permanent magnetic fields. The speeds are determined by current flow to the appropriate set of brushes inside the motor. The current flow is controlled by the multi-function switch stalk mounted wiper switch, high speed/low speed relays located in the PDC. The speed sensitive intermittent wiper is controlled by the Body Control Module (BCM). The intermittent mode, with the vehicle traveling greater than 10.4 mph, has a range of 0.5 to 18 seconds. With the vehicle traveling less than 10.4 mph, and the time delay is not adjusted, time delay doubles to a range of 1 to 36 seconds. The wiper arms will park at the base of the windshield just above the cowl cover after the wiper switch is turned OFF.

The windshield wiper motor and linkage is located in an integral wiper unit at the rear of the engine compartment. The wiper unit must be removed to gain access to the wiper motor.

When continuous rear wiper operation is required, the Body Control Module (BCM) will provide ignition ON voltage to the rear wiper motor. When the wiper switch is turned OFF, the BCM provides circuit ground to operate the motor until the wipe cycle is complete and the wiper arm returns to the base of the rear window. When intermittent rear wiper mode is selected, the wiper motor will cycle every 7 seconds. The intermittent delay time is also adjusted based upon vehicle speed. With the vehicle traveling greater at 50 mph, the cycle changes to every 5 seconds.

REAR WINDOW WIPER / WASHER SWITCHES
The rear window wiper/washer switches are incorporated into the HVAC switch panel. Refer to Instrument Panel and Systems for service procedures.