Wiper Switch: Description and Operation

Windshield Wiper Switch and Washer Switch:

RIGHT MULTI-FUNCTION SWITCH
The right multi-function switch is mounted on the right side of the steering column. The only visible part of the right multi-function switch is the control stalk that extends from the right side of the steering column just below the steering wheel. The right multi-function switch control stalk has both nomenclature and international control symbols on it, which identify its many functions. On the end of the control stalk is a plastic knob with a rounded end and a knurled band near its base to allow it to be easily rotated. The remainder of the right multi-function switch is concealed beneath the steering column shrouds. The switch housing and its control stalk are constructed of molded black plastic. A single connector receptacle containing six terminal pins is located on the back of the switch housing and connects the switch to the vehicle electrical system through a take out and connector of the instrument panel wire harness. The switch is secured to the upper steering column housing by a single screw. The right multi-function switch is the primary control for the front wiper and washer system, and contains switches, circuitry, an intermittent wipe logic circuit, and an internal wiper motor relay to provide the following features:
- Continuous Wipe Modes - The internal circuitry of the right multi-function switch provides two continuous wipe cycles, low speed or high speed.
- Intermittent Wipe Mode - The internal circuitry of the right multi-function switch provides an intermittent wipe mode with adjustable delay intervals between wipe cycles of about one second to about fifteen seconds.
- Washer Mode - When the front washer system is activated with the right multi-function switch while the front wiper system is operating, washer fluid will be dispensed onto the windshield glass through the washer nozzles for as long as the front washer pump is energized.
- Wipe-After-Wash Mode - The internal circuitry of the right multi-function switch provides a wipe-after-wash feature which, if the front wipers are turned OFF, will operate the front washer pump/motor and the front wipers for as long as the washer system is activated, then provide one or two additional wipe cycles after the washer system is deactivated before parking the front wiper blades near the base of the windshield.
The right multi-function switch cannot be adjusted or repaired. If any function of the switch is faulty, or if the switch is damaged, the entire switch unit must be replaced.

Moving the control stalk of the right multi-function switch up or down to one of four detent positions actuates the triple pole, quadruple throw front wiper switch and selects the OFF, Low, High, or Delay front wiper operating mode. Pulling the control stalk towards the steering wheel actuates the momentary single pole, single throw front washer switch and operates the front washer pump/motor. Rotating the knob on the end of the control stalk actuates the front wiper delay variable resistor and selects the wiper delay interval when the Delay mode is selected with the wiper switch. The intermittent wipe logic circuit within the right multi-function switch monitors inputs from the front wiper switch, the front washer switch, the front wiper delay variable resistor, and the front wiper motor park switch. The programming of the logic circuit then determines the proper outputs to the front wiper motor. The low current logic circuit controls the high current front wiper motor by pulling the control coil of the integral wiper motor relay to ground. The wiper motor relay switches a circuit that feeds battery current to the low speed brush of the front wiper motor.

When the ignition switch is in the Accessory or ON positions, battery current from a fuse in the Power Distribution Center (PDC) is provided to the wiper and washer system circuit breaker in the Junction Block (JB). This automatic resetting circuit breaker provides battery current through a fused ignition switch output (run-acc) circuit to the right multi-function switch. The electronic intermittent wipe logic circuit receives a logic ground through the instrument panel wire harness from a take out with an eyelet terminal connector located under a nut on a ground stud on the back of the lower instrument panel reinforcement, near the left instrument panel end bracket. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the right multi-function switch.

Fig.24 Accessory Switch Bezel:

REAR WIPER & WASHER SWITCH
The rear wiper and washer switch is located in the accessory switch bezel near the bottom of the instrument panel center stack area on the instrument panel. The single two-function switch is molded from black plastic and is secured by a snap fit in a dedicated receptacle molded into the back of the accessory switch bezel. A single six pin connector receptacle is molded into the back of the switch housing. Only the switch rocker button is visible through the lower opening of the instrument panel center bezel, the remainder of the switch is concealed behind the accessory switch bezel within the instrument panel. The rear wiper and washer switch contains switches to control both the rear wiper and the rear washer, and also has an integral incandescent illumination lamp with a serviceable bulb. The switch rocker is identified with an International Control and Display Symbol icon for windshield wiper and washer, and the icon is illuminated from behind when the exterior lamps are turned ON. The rear wiper and washer switch cannot be repaired and, if faulty or damaged, the entire switch unit must be replaced. The switch illumination lamp bulb is available for service replacement.

The rear wiper and washer switch features a detent in the Wipe position, and a momentary Wash position. The bottom of the switch rocker is pushed down to its detent to activate the rear wiper system, and down again to the momentary position to activate the rear washer system. Pushing the top of the switch rocker moves the switch to the OFF position, which also has a detent. When the ignition switch is in the ON position, battery current from a fuse in the Power Distribution Center (PDC) is provided to the rear wiper and washer system fuse in the Junction Block (JB) through a fused ignition switch output (run) circuit. The switch is connected to the vehicle electrical system through a single dedicated take out and connector in the instrument panel wire harness. The intensity of the switch illumination lamp is controlled by the panel lamps dimmer rheostat in the headlamp switch. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the rear wiper and washer switch.