Wiper and Washer Systems: Description and Operation
Front Wiper/WasherHow the Circuit Works (except Auto Wiper)
How the Circuit Works (except Auto With the ignition switch in ON (II) or START (III), battery voltage is applied to the windshield wiper motor through fuse 12 (in the driver s under dash fuse/relay box) and to the wiper/washer switch through fuse 11 (in the driver s under-dash fuse/relay box).
Low Speed
When the wiper switch is moved to LOW, the low speed winding of the motor is grounded through the LOW contact of the wiper/washer switch, and the wipers run at low speed.
Park/Off
When the wiper switch is moved to OFF, ground is provided for the low speed winding of the windshield wiper motor through the wiper switch, intermittent wiper relay, and the cam switch on the motor to G301. The wipers then run at low speed until the cam switch on the motor moves to PARK, removing the ground, which stops the wipers in the park position.
High Speed
When the wiper switch is moved to HIGH, the high speed windings of the windshield wiper motor are grounded through the HIGH contact of the wiper/ washer switch, and the wipers run at high speed.
Intermittent
When the wiper switch is moved to INT, battery voltage is applied through fuse 11 (in the driver s under dash fuse/relay box) and the wiper/washer switch to the driver s multiplex control unit which energizes the intermittent wiper relay by applying ground to the relay coil.
The wiper sweep interval is controlled by vehicle speed and the resistance of the intermittent dwell time controller. The resistance of the controller varies from 0 to 30 kOhms. The PCM sends a vehicle speed signal directly to the driver s multiplex control unit. Vehicle speed will determine the rate of the wiper cycle. If the intermittent time is set to the shortest delay, the wipers will change from intermittent to low speed operation at a driving speed above 12 mph (20 km/h). They will change back to intermittent operation when vehicle speed drops below 12 mph (20 km/h) again.
Mist
When the wiper/washer lever is pushed down and held, the high speed winding of the windshield wiper motor is grounded through the MIST contact of the wiper/washer switch. The wipers sweep at high speed until the lever is released. The PARK/OFF function then takes over and the wipers stop in the PARK position.
Washer
When the wiper/washer lever is pulled, battery voltage is applied to the windshield washer motor and the driver s multiplex control unit. The driver s multiplex control unit grounds the coil of the intermittent wiper relay. The relay, in turn, applies ground to the low speed windings of the wiper motor. The washer motor then pumps washer fluid onto the windshield and the wipers run at low speed. When the lever is released, the wipers make one more sweep and then stop.
How the Circuit Works (Auto Wiper)
With the ignition switch in ON (II) or START (III), battery voltage is applied to the windshield wiper motor and the automatic wiper relay coil through fuse 12 (in the driver's under dash fuse/relay box), to the wiper/washer switch through fuse 11 (in the driver s under-dash fuse/relay box), and to the rain sensor and automatic wiper control unit through fuse 9 (in the driver's under-dash fuse/relay box).
Low Speed
When the wiper switch is moved to LOW, the low speed winding of the windshield wiper motor is grounded through the automatic wiper relay and the LOW contact of the wiper/washer switch, and the wipers run at low speed.
Park/Off
When the wiper switch is moved to OFF, ground is provided for the low speed winding of the windshield wiper motor through the automatic wiper relay, wiper switch, intermittent wiper relay, and the cam switch on the motor to G301. The wipers then run at low speed until the cam switch on the motor moves to PARK, removing the ground, which stops the wipers in the park position.
High Speed
When the wiper switch is moved to HIGH, the high speed windings of the windshield wiper motor are grounded through the HIGH contact of the wiper/ washer switch, and the wipers run at high speed.
Automatic
When the wiper switch is moved to AUTO, battery voltage is applied through fuse 11 (in the driver s under-dash fuse/relay box) and the wiper/washer switch to the driver s multiplex control unit, rain sensor and automatic wiper control unit. The rain sensor and automatic wiper control unit will automatically power the windshield wiper motor when a predetermined amount of rain is detected.
In rain conditions where low speed wipers are needed, the rain sensor and automatic wiper control unit will energize the intermittent wiper relay by applying ground to the relay coil. The low speed winding of the windshield wiper motor is grounded through the automatic wiper relay, wiper switch, and the intermittent wiper relay to G201, and the wipers run at low speed.
In rain conditions where high speed wipers are needed, the rain sensor and automatic wiper control unit will energize the intermittent wiper relay and the automatic wiper relay by applying ground to the relay coils. The high speed winding of the windshield wiper motor is grounded through the automatic wiper relay, wiper switch, and the intermittent wiper relay to G201, and the wipers run at high speed.
In varying rain conditions where intermittent speed wipers are needed, the rain sensor and automatic wiper control unit utilizes vehicle speed information and the resistance of the intermittent dwell time controller to control the wiper sweep interval. The resistance of the intermittent dwell time controller varies from 0 to 30 kOhms. The PCM sends a vehicle speed signal directly to the driver s multiplex control unit. Vehicle speed will determine the rate of the wiper cycle. If the intermittent time is set to the shortest delay, the wipers will change from intermittent to low speed operation at a driving speed above 12 mph (20 km/h). They will change back to intermittent operation when vehicle speed drops below 12 mph (20 km/h) again.
Mist
When the wiper/washer lever is pushed down and held, the high speed winding of the windshield wiper motor is grounded through the MIST contact of the wiper/washer switch. The wipers sweep at high speed until the lever is released. The PARK/OFF function then takes over and the wipers stop in the PARK position.
Washer
When the wiper/washer lever is pulled, battery voltage is applied to the windshield washer motor and the rain sensor and automatic wiper control unit. The rain sensor and automatic wiper control unit grounds the coil of the intermittent wiper relay. The relay, in turn, applies ground to the low speed windings of the wiper motor. The washer motor then pumps washer fluid onto the windshield and the wipers run at low speed. When the lever is released, the wipers make one more sweep and then stop.