WINDSHIELD WIPER ARM AND BLADE
DESCRIPTION
All Grand Cherokee models have two 52.50 centi-
meter (20.67 inch) long windshield wiper blades with
non-replaceable rubber elements (squeegees). The
center of the wiper blade has a molded plastic pivot
block with an integral latch that is secured in a
U-shaped formation on the end of the wiper arm.
The spring-loaded wiper arms feature over-center
hinges. The spring tension of the wiper arm controls
the pressure applied to the wiper blade on the glass.
The over-center hinges allow the blades to stand off
of the glass for easy snow removal and cleaning of
the glass and squeegees.
The windshield wiper arms are secured by a nut to
the threaded studs on the two wiper pivots near the
base of the windshield. A molded plastic cap fits over
the nut for a neat appearance. Alignment marks
molded into the windshield near the base of the glass
ensure accurate wiper arm and blade installation.
Caution should be exercised to protect the rubber
wiper blade squeegees from any petroleum-based
cleaners or contaminants, which will rapidly deterio-
rate the rubber. Also, wiper squeegees exposed to the
elements for a long time tend to lose their wiping
effectiveness.
Periodic cleaning of the wiper blade squeegees is
suggested to remove deposits of salt and road film.
The wiper blades, arms, and windshield glass should
be cleaned with a sponge or cloth and windshield
washer fluid, a mild detergent, or a non-abrasive
cleaner. If the squeegees are damaged, worn, or con-
taminated the wiper blades should be replaced.
The wiper blades and wiper arms are available for
service replacement. The wiper arms and wiper
blades cannot be adjusted or repaired. If they are
faulty or damaged, they must be replaced.
OPERATION
When the wiper blades are moved back and forth
across the windshield glass, the rubber squeegees of
the wiper blade clear the glass of rain, snow and
other materials that can obstruct visibility. The
spring loaded hinges of the wiper arms determine the
pressure applied to the wiper blade on the glass. The
multiple bridge formations of the wiper blade help to
distribute the wiper arm spring pressure evenly over
the length of the squeegee, and allow the squeegee to
conform to the contour of the glass.
WINDSHIELD WIPER MOTOR, PIVOT AND
LINKAGE MODULE
DESCRIPTION
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 passen-
ger 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 bush-
ing 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.
OPERATION
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.
8K - 6
WIPER AND WASHER SYSTEMS
WJ
DESCRIPTION AND OPERATION (Continued)