Part 1A
FRONT WIPERS/WASHERSAn electrically operated intermittent front wiper and washer system is standard factory-installed safety equipment on this model. The front wiper and washer system includes the following major components, which are described in further detail elsewhere in this service information:
- Front Washer Nozzles - The two front washer nozzles are secured by integral snap features to dedicated openings near the rear of the hood panel. The washer plumbing fittings for the washer nozzles are concealed beneath the hood panel.
- Front Washer Pump/Motor - The front washer pump/motor unit is located in a dedicated hole on the lower inboard side of the washer reservoir on the top of the left front wheel house in the engine compartment. The front washer pump/motor unit is located forward of the optional rear washer pump/motor unit mounting hole.
- Front Wiper Arms - The two front wiper arms are secured to the two wiper pivots, which extend through the cowl plenum cover/grille panel located near the base of the windshield.
- Front Wiper Blades - The two front wiper blades are secured to the two front wiper arms, and are parked on the glass near the bottom of the windshield when the front wiper system is not in operation.
- Front Wiper Module - The front wiper pivots are the only visible components of the front wiper module. The remainder of the module is concealed within the cowl plenum beneath the cowl plenum cover/grille panel. The front wiper module includes the module bracket, the single front wiper motor, the front wiper linkage, and the two front wiper pivots.
- Right Multi-Function Switch - The right multi-function switch is secured to the left multi- function switch housing on the right side of the steering column lock housing. Only the control stalk and control knob of the right multi-function switch are visible. The remainder of the right multi-function switch is concealed beneath the steering column shrouds. The right multi-function switch contains all of the switches and control circuitry for the front wiper and washer system.
- Washer Reservoir - The washer reservoir is secured to the top of the left front fender wheel house, in the left front corner of the engine compartment.
Features of the front wiper and washer system include the following:
- Continuous Wipe Modes - The two-speed wiper motor and the internal circuitry of the right multi-function switch provide 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 15 seconds.
- Mist Wipe Mode - The internal circuitry of the right multi-function switch has a momentary Mist position that will operate the front wipers for a single complete cycle, then park the wiper blades near the base of the windshield.
- 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.
Hard wired circuitry connects the front wiper and washer system components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the front wiper and washer system components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.
The front wiper and washer system is intended to provide the vehicle operator with a convenient, safe, and reliable means of maintaining visibility through the windshield glass. The various components of this system are designed to convert electrical energy produced by the vehicle electrical system into the mechanical action of the wiper blades to wipe the outside surface of the glass, as well as into the hydraulic action of the washer system to apply washer fluid stored in an on-board reservoir to the area of the glass to be wiped. When combined, these components provide the means to effectively maintain clear visibility for the vehicle operator by removing excess accumulations of rain, snow, bugs, mud, or other minor debris that might be encountered while driving the vehicle under numerous types of inclement operating conditions from the outside windshield glass surface. The vehicle operator initiates all front wiper and washer system functions with the right multi-function switch control stalk that extends from the right side of the steering column, just below the steering wheel. Moving the control stalk upward selects the front wiper system operating mode. The front wiper system allows the vehicle operator to select from two continuous wiper speeds, Hi or Lo, or the intermittent wipe Delay mode. Pulling the control stalk downwards and releasing it selects the front wiper system Mist mode, which operates the front wipers for one complete wipe cycle. Rotating the control knob on the end of the control stalk allows the vehicle operator to select the intermittent wipe Delay interval. Pulling the control stalk towards the steering wheel activates the front washer pump/motor; which dispenses washer fluid onto the windshield glass through the front washer nozzles.
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 front wiper and washer system fuse in the fuse block. This fuse provides battery current through separate fused ignition switch output (run-acc) circuits to the right multi-function switch, and to the front wiper motor. Within the right multi-function switch, this battery current is fed to one side of the control coil in the wiper motor relay, and to the electronic intermittent wipe logic circuit, which are both integral to the switch. When the Lo position of the right multi-function switch control stalk is selected, the Lo position circuitry within the switch directs battery current to the low speed brush of the front wiper motor, which causes the front wipers to cycle at a low speed. When the Hi position of the control stalk is selected, the Hi position circuitry within the switch directs battery current to the high speed brush of the front wiper motor, which causes the front wipers to cycle at a high speed. In order to provide the mist feature, the Mist position circuitry within the switch momentarily directs battery current to the low speed brush of the front wiper motor, which causes the front wipers to cycle at low speed for as long as the switch is held in the Mist position, then complete the current wipe cycle and park after the switch is released.
The intermittent wipe and wipe-after-wash features of the front wiper and washer system are both provided by the electronic intermittent wipe logic circuit within the right multi-function switch. In order to provide the intermittent wipe feature, the logic circuit monitors the wiper switch state, the intermittent delay resistance setting, and the wiper motor park switch state. In order to provide the wipe-after-wash feature, the logic circuit monitors both the front washer switch state and the wiper motor park switch state. When the Delay position of the right multi- function switch control stalk is selected, the Delay position circuitry within the switch directs battery current to a request input of the logic circuit. The Delay position circuitry also directs battery current through an internal variable resistor to the intermittent wipe delay sense input of the logic circuit, which indicates the delay interval that has been selected by the vehicle operator. The logic circuit responds to the Delay mode request inputs by calculating the correct delay interval. The logic circuit then energizes the wiper motor relay by pulling the relay control coil to ground. The energized wiper motor relay directs battery current from the normally open relay terminal through the common feed relay terminal and the Delay position wiper switch circuitry to the low speed brush of the wiper motor. The logic circuit monitors the front wiper motor operation through the wiper park switch sense circuit, which allows the logic circuit to determine the proper timing to begin the next wiper blade sweep.
When the OFF position of the right multi-function switch control stalk is selected, one of two events is possible. The event that will occur depends upon the position of the wiper blades on the windshield at the moment that the OFF position is selected. If the wiper blades are in the down position on the windshield when the OFF position is selected, the park switch that is integral to the front wiper motor is closed to ground and the wiper motor ceases to operate. If the wiper blades are not in the down position on the windshield at the moment the OFF position is selected, the park switch is closed to battery current through the fused ignition switch output (run-acc) circuit of the front wiper motor. The park switch sense circuit directs this battery current to the low speed brush of the wiper motor through the normally closed circuit of the wiper motor relay and the OFF position circuitry of the wiper switch. This causes the wiper motor to continue running until the wiper blades are in the down position on the windshield and the park switch is again closed to ground.
When the Wash position of the right multi-function switch control stalk is selected, the Wash position circuitry within the switch directs battery current to the front washer pump/motor. The intermittent wipe logic circuit monitors the washer switch state through a washer switch sense input. When the washer switch is closed with the front wiper system turned Off, the intermittent wipe logic circuit operates the front wiper motor through the wiper motor relay in the same manner as it does to provide the Delay mode operation, but uses the OFF position circuitry of the wiper switch to feed battery current to the low speed brush of the front wiper motor. When the Wash position circuitry state changes to open, the intermittent wipe logic circuit monitors the front wiper motor through the wiper park switch sense circuit, which allows the logic circuit to count the number of wiper blade sweeps.
Refer to the owner's manual in the vehicle glove box for more information on the features and operation of the front wiper and washer system.
Fig.2 Front Washer Plumbing:
FRONT CHECK VALVE
Two front washer system check valves are standard equipment on this model, and are installed in the front washer system plumbing. The front check valves are located in the engine compartment in the washer supply hose for each front washer nozzle between the molded plastic hose tee fitting and the washer nozzle. The check valve consists of a molded plastic valve body with a raised center that is tapered in the direction of the flow through the valve. A barbed hose nipple is formed on each side of the raised center of the valve body. Within the check valve body, a small check ball is held against an integral valve seat at one end of the valve by a small coiled spring. The front check valve cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
The front check valve provides more than one function in this application. It prevents washer fluid from draining out of the front washer supply hoses back to the washer reservoir. This drain-back would result in a lengthy delay from when the front washer switch is actuated until washer fluid was dispensed through the front washer nozzles, because the front washer pump would have to refill the front washer plumbing from the reservoir to the nozzle. Also, the front check valve prevents washer fluid from siphoning through the front washer nozzles after the front washer system is turned OFF. When the front washer pump pressurizes and pumps washer fluid from the reservoir through the front washer plumbing, the fluid pressure overrides the spring pressure applied to the check ball within the valve and unseats the check ball, allowing washer fluid to flow toward the front washer nozzle, When the front washer pump stops operating, spring pressure seats the check ball in the valve and fluid flow in either direction within the front washer plumbing is prevented. The front check valve cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.