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Jeep Liberty KJ. Manual - part 319

REMOVAL

1. Unlatch and open the hood.

2. Disconnect and isolate the battery negative cable.

3. Remove both front wiper arms from the wiper piv-

ots. (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS - FRONT/FRONT WIPER ARM - REMOVAL).

4. Remove the cowl plenum cover/grille panel from

over the cowl plenum. (Refer to 23 - BODY/EXTE-
RIOR/COWL GRILLE - REMOVAL).

5. Disconnect the headlamp and dash wire harness

connector (5) for the front wiper motor from the
motor pigtail wire connector.

6. Remove the two screws (2) that secure the front

wiper module (3) to the top of the cowl plenum
panel at the pivot brackets.

7. Remove the two nuts (1) that secure the front

wiper module to the two weld studs (4) on the bottom of the cowl plenum panel.

8. Lift the front wiper module up from the cowl plenum panel far enough to disengage the two lower insulators from

the weld studs on the bottom of the plenum panel.

9. Remove the front wiper module from the cowl plenum panel as a unit.

INSTALLATION

1. Position the front wiper module (3) to the cowl ple-

num as a unit.

2. Lower the front wiper module lower mounting insu-

lators over the two weld studs (4) on the bottom of
the cowl plenum panel.

3. Install the two screws (2) that secure the front

wiper module to the top of the cowl plenum panel
at the pivot brackets. Tighten the screw on the
driver side, followed by the screw on the passenger
side. Tighten the screws to 8 N·m (72 in. lbs.).

4. Install and tighten the two nuts (1) that secure the

front wiper module to the two weld studs on the
bottom of the cowl plenum panel. Tighten the nuts
to 8 N·m (72 in. lbs.).

5. Reconnect the headlamp and dash wire harness

connector (5) for the front wiper motor to the motor
pigtail wire connector.

6. Reinstall the cowl plenum cover/grille panel over the cowl plenum. (Refer to 23 - BODY/EXTERIOR/COWL

GRILLE - INSTALLATION).

7. Close and latch the hood.

8. Reinstall both front wiper arms onto the wiper pivots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/WASHERS/

FRONT WIPER ARM - INSTALLATION).

9. Reconnect the battery negative cable.

8R - 68

WIPERS/WASHERS - SERVICE INFORMATION

WIPER ON/OFF RELAY

DESCRIPTION

The wiper on/off relay is located in the Power Distri-
bution Center (PDC) in the engine compartment near
the battery. The wiper on/off relay is a conventional
International Standards Organization (ISO) micro relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The relay is
contained within a small, rectangular, molded plastic
housing and is connected to all of the required inputs
and outputs by five integral male spade-type terminals
that extend from the bottom of the relay base.

The wiper on/off relay cannot be adjusted or repaired and, if inoperative or damaged, the unit must be replaced.

OPERATION

The wiper on/off relay is an electromechanical switch that uses a low current input from the Body Control Module
(BCM) to control a high current output to the front wiper motor. The movable common feed contact point is held
against the fixed normally closed contact point by spring pressure. When the relay coil is energized, an electromag-
netic field is produced by the coil windings. This electromagnetic field draws the movable relay contact point away
from the fixed normally closed contact point, and holds it against the fixed normally open contact point. When the
relay coil is de-energized, spring pressure returns the movable contact point back against the fixed normally closed
contact point. A resistor is connected in parallel with the relay coil in the relay, and helps to dissipate voltage spikes
and electromagnetic interference that can be generated as the electromagnetic field of the relay coil collapses.

The wiper on/off relay terminals are connected to the vehicle electrical system through a connector receptacle in the
Power Distribution Center (PDC). The inputs and outputs of the wiper on/off relay include:

•

Common Feed Terminal - The common feed terminal (30) is connected to the common feed terminal of the
wiper high/low relay at all times through the wiper on/off relay output circuit. Therefore, the wiper high/low relay
is able to control the wiper motor speed only when the wiper on/off relay is energized.

•

Coil Ground Terminal - The coil ground terminal (85) is connected to a control output of the Body Control
Module (BCM) through the front wiper on/off relay control circuit. The BCM controls front wiper motor operation
by controlling a ground path through this circuit.

•

Coil Battery Terminal - The coil battery terminal (86) receives battery current at all times from a circuit
breaker in the Junction Block (JB) through a fused ignition switch output (run-acc) circuit.

•

Normally Open Terminal - The normally open terminal (87) receives battery current from a circuit breaker in
the Junction Block (JB) through a fused ignition switch output (run-acc) circuit. When the front wiper on/off
relay is energized, the wiper high/low relay is able to control the wiper motor speed.

•

Normally Closed Terminal - The normally closed terminal (87A) is connected to the wiper park switch in the
front wiper motor through the front wiper park switch sense circuit, and is connected to the wiper park switch
whenever the relay is de-energized.

The wiper on/off relay can be diagnosed using conventional diagnostic tools and methods.

WIPERS/WASHERS - SERVICE INFORMATION

8R - 69

NAVIGATION/TELECOMMUNICATION

TABLE OF CONTENTS

page

NAVIGATION/TELECOMMUNICATION -

ELECTRICAL DIAGNOSTICS. . . . . . . . . . . . . . . . . 1

NAVIGATION/TELECOMMUNICATION . . . . . . . . . . 76

NAVIGATION/TELECOMMUNICATION - ELECTRICAL

DIAGNOSTICS

TABLE OF CONTENTS