Grand Cherokee 2WD V8-4.7L VIN N (2000)
Wiper Motor Linkage: Description and Operation
The windshield wiper motor, pivot and linkage module is secured with four screws through rubber isolators to the cowl plenum panel beneath the cowl
plenum cover/grille panel. The two-speed permanent magnet windshield wiper motor has an integral transmission and park switch. The park switch
opens and closes as the wiper motor operates. When the wipers are up off the base of the windshield, the park switch is closed; and, when the wipers are
near the base of the windshield (parked), the park switch is open. The wiper motor is secured below the center of the module bracket with three screws.
The wiper motor output shaft passes through a clearance hole, where a nut secures the wiper motor crank arm to the motor output shaft above the module
bracket.
The two wiper pivots are secured at the ends of the module bracket. The two wiper pivot lever arms and the wiper motor crank arm each have ball studs
on their ends. The motor crank arm ball stud is the longer of the three. Two drive links connect the motor crank arm to the pivot lever arms. The
passenger side drive link has a plastic socket-type bushing on each end. The driver side drive link has a plastic socket-type bushing on one end, and a
plastic sleeve- type bushing on the other end. The socket-type bushing on one end of each drive link is snap-fit over the ball stud on the lever arm of its
respective pivot. The driver side drive link sleeve-type bushing end is then fit over the motor crank arm ball stud, and the other socket-type bushing of
the passenger side drive link is snap-fit over the exposed end of the motor crank arm ball stud.
The wiper motor, pivots, linkage, bushings, motor crank arm and mounting bracket are only serviced as a complete unit. If any part of this unit is faulty
or damaged, the entire wiper motor pivot and linkage module must be replaced.
The windshield wiper motor speed is controlled by current flow to the proper set of brushes. When the wiper motor is turned on, the park switch provides
the Body Control Module (BCM) with a pulse signal that allows the BCM wiper system logic to monitor the number and frequency of the wipe cycles.
When the wiper motor is turned off, the closed park switch (wipers up) provides battery voltage to the wiper motor until the park switch opens (wipers
down or parked). The wiper motor crank arm, linkage and pivots convert the rotary action of the wiper motor output shaft to the back and forth wiping
motion of the wiper arms and blades.
