Wiper and Washer Systems: Description and Operation

Front Wiper/Washer

How the Circuit Works

Low Speed
With the ignition switch in ON (II) or START (III), battery voltage is applied to the windshield wiper motor through fuse 20 (in the under-dash fuse/relay box). When you move the wiper switch 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 you turn off the wiper switch, ground is provided for the low speed winding of the windshield wiper motor through the wiper switch 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 you move the wiper switch 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 you move the wiper switch to INT battery voltage is applied through fuse 20 (in the under-dash fuse/relay box) to the multiplex control unit which provides a ground through the wiper/washer switch to the low speed windings of the windshield wiper motor. The wipers make a single sweep every few seconds.

Mist
When you push the wiper/washer lever down and hold it, the high speed winding of the windshield wiper motor is grounded through the MIST contact in the wiper/washer switch. The wipers sweep at high speed until you release the lever. The PARK/OFF function then takes over and the wipers stop in the PARK position.

When you pull the wiper/washer lever toward you, battery voltage is applied to the windshield washer motor and the multiplex control unit. The multiplex control unit 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 you release the lever, the wipers make one more sweep and then stop.