Wiper and Washer Systems: Description and Operation

Circuit Description

FRONT WIPER & WASHER
All functions of the front wiper and washer circuit are controlled by the position of the front wiper and washer switch. The wiper switch has 4 positions: OFF, NT, LO and HI.

Wiper operation

1. Low (LO) and High (HI) position
The front wiper motor has two separate brushes for low and high speed operation.When the wiper switch is in LO or HI position, ground is applied to the appropriate brushes through the wiper switch in the multifunction switch.

2. INT position
When the wiper switch is turned to INT, the ETACM receives the INT signal and INT delay time signal. According to these signals, the control module controls the operation of the front wiper through wiper motor relay coil control Ground is applied to the low speed brush of the front wiper motor through the closed contact of the wiper motor relay.

The remainder of the wipers' sweep is controlled by the park circuit. The cycle repeats as long as the wiper switch is in NT and the pause interval between sweeps is determined by the ETACM.

3. OFF position
When the wiper switch is turned to OFF from another position (INT, LO and HI) and the wiper is not at the rest (out of park) position, the low speed brush of the front wiper motor is grounded through the parking switch in the front wiper motor.

Washer operation
The front wiper motor operates as long as the washer switch is pulled. When the washer switch is pulled, the control module controls the low speed operation of the front wiper motor through the wiper motor relay control.

REAR WIPER & WASHER
All functions of the rear wiper and washer circuits are controlled by the position of the rear wiper & washer switch in the multifunction switch. According to the switch signals, the relay control circuit (in the rear intermittent wiper relay) controls the relay operations. The rear window wiper and washer are turned ON/OFF by depressing the button. Washer fluid is sprayed on the glass as long as the button is depressed.
1. When the "ON (wiper)" position is depressed, the rear window wiper starts to operate continuously.
2. When the "INT" position is depressed, the wiper operates every five seconds intermittently.
3. When the "Washer" position is depressed, the rear window wiper wipes the window three times after the washer fluid sprays onto the rear window.