Wiper and Washer Systems: Description and Operation
How the Circuit WorksLow Speed
With the ignition switch in ON (II), battery voltage is applied to the windshield wiper motor through fuse 8, and to the windshield wiper/washer switch through fuse 12. 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, 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 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 12 and the windshield wiper/washer switch to the CPU in the gauge assembly. The CPU sends a signal to the wiper/washer driving circuit which energizes the intermittent wiper relay by applying a ground signal to the relay coil. The wipers then make a single sweep every few seconds.
Mist
When you push the wiper/washer lever up 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 will sweep at high speed as long as you hold the lever up. When you release the lever, the PARK/OFF function then takes over and the wipers stop in the PARK position.
Washer
When you pull the wiper/washer lever toward you, battery voltage is applied to the windshield washer motor and the CPU in the gauge assembly. The CPU grounds the coil of the intermittent wiper relay. The relay, in turn, grounds 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.