Grand Cherokee 2WD Limited V8-4.7L (2002)
Wiper Control Module: Description and Operation
Front Wiper Module
Fig.11 Front Wiper Module
FRONT WIPER MODULE
The front wiper module is secured with four screws through rubber isolators to the cowl plenum panel beneath the cowl plenum cover/grille panel. The
ends of the wiper pivot shafts that protrude through dedicated openings in the cowl plenum cover/grille panel to drive the wiper arms and blades are
the only visible components of the front wiper module.
The front wiper module consists of the following major components:
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Bracket - The front wiper module bracket consists of a long tubular steel main member that has a stamped pivot bracket formation near each end
where the two wiper pivots are secured. A stamped steel mounting plate for the wiper motor is secured with welds near the center of the main
member.
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Crank Arm - The front wiper motor crank arm is a stamped steel unit with a slotted hole on the driven end that is secured to the wiper motor output
shaft with a nut, and a ball stud secured to the drive end.
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Linkage - Two stamped steel drive links connect the wiper 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 wiper motor crank arm ball stud.
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Motor - The front wiper motor is secured with three screws to the motor mounting plate near the center of the wiper module bracket. The wiper
motor output shaft passes through a hole in the module bracket, where a nut secures the wiper motor crank arm to the motor output shaft. The
two-speed permanent magnet wiper motor features an integral transmission, an internal park switch, and an internal automatic resetting circuit
breaker.
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Pivots - The two front wiper pivots are secured to the ends of the wiper module bracket. The crank arms that extend from the bottom of the pivot
shafts each have a ball stud on their end. The upper end of each pivot shaft where the wiper arms will be fastened each has an externally serrated
drum with a threaded stud secured to it.
The front wiper module cannot be adjusted or repaired. If any component of the module is faulty or damaged, the entire front wiper module unit must
be replaced. The reinforcement bracket and stud plate are available for service replacement.
The front wiper module operation is controlled by the battery current inputs received by the wiper motor from the wiper ON/OFF and wiper high/low
relays. The wiper motor speed is controlled by current flow to either the low speed or the high speed set of brushes. The park switch is a single pole,
single throw, momentary switch within the wiper motor that is mechanically actuated by the wiper motor transmission components. The park switch
alternately closes the wiper park switch sense circuit to ground or to battery current, depending upon the position of the wipers on the glass. This
feature allows the motor to complete its current wipe cycle after the wiper system has been turned Off, and to park the wiper blades in the lowest
portion of the wipe pattern. The automatic resetting circuit breaker protects the motor from overloads. The wiper motor crank arm, the two wiper
linkage members, and the two wiper pivots mechanically convert the rotary out-put of the wiper motor to the back and forth wiping motion of the
wiper arms and blades on the glass.
