Dodge Ram Truck 1500-2500-3500. Manual — part 608

WIPER MODULE

DESCRIPTION

The wiper module is secured with screws through
three rubber grommet-type insulators (5) to the cowl
plenum panel. The module is concealed beneath the
molded plastic cowl plenum cover/grille panel between
the base of the windshield and the rear edge of the
hood panel. The ends of the pivot shafts protruding
through openings in the cowl plenum cover/grille panel
to drive the wiper arms and blades are the only visible
components of the wiper module. The wiper module
consists of the following major components:

•

Bracket - The wiper module bracket consists of a long tubular steel main member (2) that has a die cast pivot
bracket (1) at each end to which the two wiper pivots are secured. A stamped steel clamp secures the center
of the tubular member to the die cast bracket integral to the wiper motor with two screws.

•

Crank Arm (10) - The 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 has a ball stud secured to the drive end.

•

Linkage (2) - Two stamped steel drive links connect the wiper motor crank arm to the wiper pivot lever arms.
The left side drive link has a plastic socket-type bushing (6) on each end. The right 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 (8) of its respective pivot. The right
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 left side drive link is snap-fit over the exposed end of the wiper motor crank arm ball stud.

•

Motor (11) - The wiper motor features an integral die cast bracket to which the wiper module bracket is
secured with a stamped steel clamp and two screws near the top and which has a single rubber insulated
mounting ear at the bottom. This die casting also serves as the wiper motor transmission housing from which
the wiper motor output shaft exits. 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.

•

Pivots (2) - The two front wiper pivots are secured within the die cast pivot brackets on the outboard ends of
the wiper module main member. The lever arms that extend from the center 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 a
serrated driver with a keyway. The lower ends of the pivot shafts are installed through lubricated bushings in
the pivot brackets and are secured with snap rings.

The wiper module cannot be adjusted or repaired. If any component of the module is faulty or damaged, the entire
wiper module unit must be replaced.

OPERATION

The wiper module operation is controlled by the battery current inputs received by the wiper motor through 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 opens and
closes the wiper park switch sense circuit to ground, 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

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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 output of the wiper motor to the back and forth wiping motion of the wiper arms and blades on the glass.

REMOVAL

1. Remove both wiper arms (4) from the wiper pivots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/WIPER ARM

- REMOVAL).

2. Unlatch and open the hood.

3. Disconnect and isolate the battery negative cable.

4. Remove the cowl plenum cover/grille panel (5) from over the cowl plenum (8). (Refer to 23 - BODY/EXTERIOR/

COWL GRILLE - REMOVAL).

5. Disconnect the left headlamp and dash wire harness connector (7) for the wiper motor from the motor pigtail wire

connector.

6. Remove the two screws (9) that secure the wiper module (6) to the top of the cowl plenum panel at the pivot

brackets.

7. Remove the screw that secures the wiper module to the bottom of the cowl plenum panel.

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

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INSTALLATION

1. Position the wiper module (6) into the cowl plenum (8) as a unit.

2. Install the two screws (9) that secure the 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
(75 in. lbs.).

3. Install and tighten the screw that secures the wiper module to the bottom of the cowl plenum panel. Tighten the

screw to 8 N·m (75 in. lbs.).

4. Reconnect the left headlamp and dash wire harness connector (7) for the wiper motor to the motor pigtail wire

connector.

5. Reinstall the cowl plenum cover/grille panel (5) over the cowl plenum. (Refer to 23 - BODY/EXTERIOR/COWL

GRILLE - INSTALLATION).

6. Reconnect the battery negative cable.

7. Close and latch the hood.

8. Reinstall both wiper arms (4) onto the wiper pivots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/WIPER

ARMS - INSTALLATION).

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WIPER ON/OFF RELAY

DESCRIPTION

The wiper on/off relay is a conventional International
Standards Organization (ISO) micro relay. Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminal patterns,
and terminal functions. This relay is contained within a
small, rectangular, molded plastic housing and is con-
nected to all of the required inputs and outputs
through five integral male spade-type terminals that
extend from the relay base plate.

The wiper on/off relay is located in the Power Distribution Center (PDC)/Integrated Power Module (IPM) in the
engine compartment near the battery. Refer to the layout label on the underside of the PDC cover for specific relay
cavity assignment information. The wiper on/off relay cannot be adjusted or repaired and, if faulty 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 Front Control Module
(FCM) to control a high current output to the 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 electromagnetic 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)/Integrated Power Module (IPM). 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.

•

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

•

Coil Battery Terminal - The coil battery terminal (86) receives battery current at all times from a fuse in the
PDC/IPM through a fused ignition switch output (run-acc) circuit.

•

Normally Open Terminal - The normally open terminal (87) receives battery current at all times from a fuse
in the IPM through a fused ignition switch output (run-acc) circuit, and provides battery current to the wiper
on/off relay output circuit whenever the relay is energized.

•

Normally Closed Terminal - The normally closed terminal (87A) is connected to ground at all times through
a take out of the left headlamp and dash wire harness with an eyelet terminal connector that is secured by a
screw to the front end sheet metal, and is connected to the wiper on/off relay output circuit whenever the relay
is de-energized.

The wiper on/off relay may be diagnosed using conventional diagnostic tools and methods. However, conventional
diagnostic methods may not prove conclusive in the diagnosis of the ElectroMechanical Instrument Cluster (EMIC),
the FCM, or the electronic message inputs to or outputs from the EMIC and the FCM that control the operation of
the wiper on/off relay. The most reliable, efficient, and accurate means to diagnose the wiper on/off relay, the EMIC,
the FCM, or the electronic message inputs and outputs related to the wiper on/off relay operation requires the use
of a diagnostic scan tool. Refer to the appropriate diagnostic information.

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