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Fig.1 Front Wiper & Washer System:

FRONT WIPERS/WASHERS
An 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 with rivets to dedicated openings in the cowl plenum cover/grille panel located near the base of the windshield. The washer plumbing fittings for the washer nozzles are concealed beneath the cowl plenum cover/grille panel.
- Front Washer Pump/Motor - The front washer pump/motor unit is located in a dedicated hole on the lower outboard side of the washer reservoir, ahead of the left front wheel housing. The front washer pump is located below the optional rear washer pump 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 wind- shield 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 right side of the upper steering column housing. Only the control stalk for the right multi-function switch is visible, the remainder of the 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 Fluid Level Switch - The washer fluid level switch is located in a dedicated hole near the center of the forward surface of the washer reservoir, ahead of the left front wheel housing.
- Washer Reservoir - The washer reservoir is concealed between the left inner fender shield and the left outer fender panel, above and forward of the left front wheel housing.
- Washer Reservoir Filler Neck - The washer reservoir filler neck is located on the left inner fender shield, above the left front wheel housing in 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 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.

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.

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 from the outside windshield glass surface that might be encountered while driving the vehicle under numerous types of inclement operating conditions. 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. Rotating the knob on the end of the control stalk allows the vehicle operator to select the 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 wiper and washer system circuit breaker in the Junction Block (JB). This automatic resetting circuit breaker 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 windshield wipers to cycle at a high speed.

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.3 Front Washer Plumbing:

FRONT WASHER HOSES/TUBES
The front washer plumbing consists of a small diameter rubber hose that is integral to and routed with the headlamp and dash wire harness from the barbed outlet nipple of the front washer pump/motor on the washer reservoir to the cowl plenum area. The washer hose passes from the engine compartment into the cowl plenum area through a dedicated hole near the center of the cowl top extension panel. A small plastic retaining clip secures the loose end of the washer hose to the cowl top extension panel within the cowl plenum area. The washer hose is then mated to the barbed nipple of a molded plastic tee fitting. This tee fitting is mated to two additional short lengths of washer hose, which are then mated to the barbed nipple of the two front washer nozzles in the cowl grille panel.

Washer hose is available for service only as roll stock, which must then be cut to length. For service replacement of the hose that is integral to the headlamp and dash wire harness, it is suggested that a suitable length of washer hose be carefully routed along and secured to the outside of the harness. The molded plastic washer hose fittings cannot be repaired. If these fittings are faulty or damaged, they must be replaced.

Washer fluid in the washer reservoir is pressurized and fed by the front washer pump/motor through the front washer system plumbing and fittings to the two front washer nozzles. Whenever routing the washer hose or a wire harness containing a washer hose, it must be routed away from hot, sharp, or moving parts; and, sharp bends that might pinch the hose must be avoided.

Fig.4 Front Washer Nozzles:

FRONT WASHER NOZZLE
The two front washer nozzles are secured with rivets within raised pocket formations in the cowl plenum cover/grille panel located near the base of the windshield. Only the washer nozzle orifice is visible through a small opening in the raised mounting pocket that faces the windshield glass. The washer plumbing fittings for the washer nozzles are concealed beneath the cowl plenum cover/grille panel. These fluidic washer nozzles are constructed of molded plastic. The cowl plenum cover/grille panel must be removed from the vehicle to access the nozzles for service. The washer nozzles cannot be adjusted or repaired. If faulty or damaged, they must be replaced.

The two front washer nozzles are designed to dispense washer fluid into the wiper pattern area on the outside of the windshield glass. Pressurized washer fluid is fed to each nozzle from the washer reservoir by the front washer pump/motor through a single hose, which is attached to a barbed nipple on each front washer nozzle below the cowl plenum cover/ grille panel. The washer nozzles incorporate a fluidic design, which causes the nozzle to emit the pressurized washer fluid as an oscillating stream to more effectively cover a larger area of the glass area to be cleaned.

Fig.7 Washer Reservoir:

FRONT WASHER PUMP/MOTOR
The front washer pump/motor unit is located on the outboard side and near the front of the washer reservoir, between the left front inner and outer fender panels. A small permanently lubricated and sealed electric motor is coupled to the rotor-type washer pump. A seal flange with a barbed nipple on the pump housing passes through a rubber grommet seal installed in one of two dedicated mounting holes near the bottom of the washer reservoir. The front washer pump/motor unit is always mounted in the lower pump mounting hole of the reservoir. The washer pump/motor unit is retained on the reservoir by the interference fit between the barbed pump nipple and the grommet seal, which is a light press fit. The front washer pump/motor unit cannot be repaired. If faulty or damaged, the entire washer pump/motor unit must be replaced.

The front washer pump/motor unit is connected to the vehicle electrical system through a single take out and two-cavity connector of the headlamp and dash wire harness. The washer pump/motor is grounded at all times through a take out of the headlamp and dash wire harness with a single eyelet terminal connector that is secured under a ground screw to the top of the left front fender wheel housing in the engine compartment. The front washer pump/motor receives battery current through the closed contacts of the momentary front washer switch within the right multi-function switch only when the switch control stalk is pulled towards the steering wheel. Washer fluid is gravity-fed from the washer reservoir to the inlet side of the washer pump. When the pump motor is energized, the rotor-type pump pressurizes the washer fluid and forces it through the pump outlet nipple, the front washer plumbing, and the front washer nozzles onto the windshield glass.

Fig.10 Wiper Arm:

FRONT WIPER ARM
The front wiper arms are the rigid members located between the wiper pivots that protrude from the cowl plenum cover/grille panel near the base of the windshield and the wiper blades on the windshield glass. The wiper arm has a die cast metal pivot end. On the underside of this pivot end is a socket formation with internal serrations and a small, movable, stamped steel latch plate that is secured loosely under a small strap that is staked to the pivot end. The wide end of a tapered, stamped steel channel is secured with a hinge pin to the pivot end of the wiper arm. One end of a long, rigid, stamped steel strap, with a small hole near its pivot end, is riveted and crimped within the narrow end of the stamped steel channel. The tip of the wiper blade end of this strap is bent back under itself to form a small hook. Concealed within the stamped steel channel, one end of a long spring is hooked through a hole in a small stamped steel strap on the hinge pin within the die cast pivot end, while the other end of the spring is hooked through the small hole in the steel strap. The entire wiper arm has a satin black finish applied to all of its visible surfaces.

A wiper arm cannot be adjusted or repaired. If damaged or faulty, the entire wiper arm unit must be replaced.

The front wiper arms are designed to mechanically transmit the motion from the wiper pivots to the wiper blades. The wiper arm must be properly indexed to the wiper pivot in order to maintain the proper wiper blade travel on the glass. The socket formation with internal serrations in the wiper arm pivot end interlocks with the serrations on the outer circumference of the wiper pivot driver, allowing positive engagement and finite adjustment of this connection. The latch plate on the underside of the wiper arm pivot end locks the wiper arm to the wiper pivot when in its installed position and, when in its unlocked position, also serves as a blocker to hold the spring-loaded wiper arm off of the glass to facilitate removal and installation. The spring-loaded wiper arm hinge controls the down-force applied through the tip of the wiper arm to the wiper blade on the glass. The hook formation on the tip of the wiper arm provides a cradle for securing and latching the wiper blade pivot block to the wiper arm.

Fig.14 Wiper Blade - Typical:

FRONT WIPER BLADE
Each front wiper blade is secured by an integral latching pivot block to the hook formation on the tip of the front wiper arms, and rests on the glass near the base of the windshield when the wipers are not in operation. The wiper blade consists of the following components:
- Superstructure - The superstructure includes several stamped steel bridges and links with claw formations that grip the wiper blade element. Also included in this unit is the latching, molded plastic pivot block that secures the superstructure to the wiper arm. All of the metal components of the wiper blade have a satin black finish applied.
- Element - The wiper element or squeegee is the resilient rubber member of the wiper blade that contacts the glass.
- Flexor - The flexor is a rigid metal component running along the length of each side of the wiper element where it is gripped by the claws of the superstructure.

ALL Cherokee models have two 45.72-centimeter (18-inch) front wiper blades with non-replaceable elements (squeegees). The wiper blades cannot be adjusted or repaired. If faulty, worn, or damaged the entire wiper blade unit must be replaced.

The wiper blade is moved back and forth across the glass by the wiper arms when the wipers are being operated. The wiper blade superstructure is the flexible frame that grips the wiper blade element and evenly distributes the force of the spring-loaded wiper arm along the length of the element. The combination of the wiper arm force and the flexibility of the superstructure makes the element conform to and maintain proper contact with the glass, even as the blade is moved over the varied curvature found across the glass surface. The wiper element flexor provides the claws of the blade superstructure with a rigid, yet flexible component on the element which can be gripped. The rubber element is designed to be stiff enough to maintain an even cleaning edge as it is drawn across the glass, but resilient enough to conform to the glass surface and flip from one cleaning edge to the other each time the wiper blade changes directions.