1998 DODGE RAM 1500 Power seats

POWER SEATS
TABLE OF CONTENTS
page page
POWER SEATS
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM............................13
DRIVER SEAT SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
PASSENGER SEAT SWITCH
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - PASSENGER
SEAT SWITCH........................16REMOVAL.............................16
INSTALLATION.........................16
POWER SEAT TRACK
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - POWER SEAT
TRACK.............................17
REMOVAL.............................17
INSTALLATION.........................17
LUMBAR CONTROL SWITCH
DESCRIPTION.........................17
OPERATION...........................18
REMOVAL.............................18
LUMBAR MOTOR
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - LUMBAR MOTOR . 18
POWER SEATS
DESCRIPTION
The power seat system option allows the driver or
passenger to electrically adjust the seat position for
optimum control and comfort using the power seat
switches located on the outboard seat cushion side
shield. The power seat system allows the seating
position to be adjusted forward, rearward, front up,
front down, rear up, or rear down. The power seat
system receives battery current through a fuse in the
Integrated Power Module, regardless of the ignition
switch position. The power seat system includes the
following components:
²Driver Power Seat Switch
²Passenger Power Seat Switch
²Driver Power Seat Track
²Passenger Power Seat Track
²Power Lumbar Adjuster(s)
Some models equipped with the power seat option
also feature a power operated lumbar support in the
seat back. The power lumbar support allows the user
to inflate or deflate a bladder located in the lower
seat back to achieve optimum comfort and support in
the lower lumbar region of the spinal column. The
power lumbar support shares the battery feed circuit
of the power seat system.
Following are general descriptions of the major
components in the power seat system. Refer to
Heated Seat Systemfor information on the individ-ually controlled heated front seats. Refer to the own-
er's manual in the vehicle glove box for more
information on the features, use and operation of the
power seat system.
OPERATION
The power seat system allows the driver and/or
front passenger seating positions to be adjusted elec-
trically and independently using the separate power
seat switches found on the outboard seat cushion
side shield of each front seat. See the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
Before any testing of the power seat system is
attempted, the battery should be fully-charged and
all wire harness connections and pins checked to
ensure proper continuity and grounds. For circuit
descriptions and diagrams, refer to Wiring Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
the dome lamp does not dim, proceed with testing of
the individual components and circuits.
DRPOWER SEATS 8N - 13

DRIVER SEAT SWITCH
DESCRIPTION
The power seat on this model can be adjusted in
eight different directions, up, down, front up, front
down, rear up, rear down, rearward and forward.
The power seat switch (Fig. 1) on this model has an
additional switch knob for adjusting the power lum-
bar support. The power seat switch is located on the
outboard side of the seat cushion on the seat cushion
side shield. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch
assembly cannot be repaired. If one switch is dam-
aged or faulty, the entire power seat switch assembly
must be replaced.
OPERATION
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch ismoved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 2). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL UP A-E, A-M, B-N, B-J
VERTICAL DOWN A-J, A-N, B-M, B-E
Fig. 1 DR Power Seat Switch
1 - POWER SEAT SWITCH ASSEMBLY
2 - FRONT SEAT CUSHION ADJUSTMENT BUTTON
3 - COMPLETE SEAT ADJUSTMENT BUTTON
4 - REAR SEAT CUSHION ADJUSTMENT BUTTON
5 - LUMBAR ADJUSTMENT BUTTON
Fig. 2 Testing Driver Power Seat Switch
8N - 14 POWER SEATSDR

DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT UP A-M, B-N
FRONT TILT DOWN A-N, B-M
REAR TILT UP A-E, B-J
REAR TILT DOWN A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (INFLATE) O-P, Q-R
LUMBAR DOWN
(DEFLATE)O-R, P-Q
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the seat cushion side shield from the
seat. Refer to the Body section of the service manual
for the procedure.
(3) Pull the switch bezel or side shield unit out
from the seat far enough to access the switch wire
harness connector. Gently pry the locking tabs of the
switch away from the wire harness connector and
carefully unplug the connector from the power seat
switch module.
(4) Remove the screws that secure the power seat
switch.
INSTALLATION
(1) Position the power seat switch on the seat
cushion side shield and install the screws that secure
the power seat switch to seat cushion side shield.
(2) Connect the electrical connector.
(3) Install the seat cushion side shield on the seat.
Refer to the Body section of the service manual for
the procedure.
(4) If equipped, install the screw that secures the
recliner lever to the recliner mechanism release shaft
on the outboard side of the front seat.
(5) Connect the battery negative cable.
PASSENGER SEAT SWITCH
DESCRIPTION
The power seat on this model can be adjusted in
eight different directions, up, down, front up, front
down, rear up, rear down, rearward and forward.
The power seat switch (Fig. 3) on this model has an
additional switch knob for adjusting the power lum-bar support. The power seat switch is located on the
outboard side of the seat cushion on the seat cushion
side shield. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch
assembly cannot be repaired. If one switch is dam-
aged or faulty, the entire power seat switch assembly
must be replaced.
OPERATION
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
Fig. 3 DR Power Seat Switch
1 - POWER SEAT SWITCH ASSEMBLY
2 - FRONT SEAT CUSHION ADJUSTMENT BUTTON
3 - COMPLETE SEAT ADJUSTMENT BUTTON
4 - REAR SEAT CUSHION ADJUSTMENT BUTTON
5 - LUMBAR ADJUSTMENT BUTTON
DRPOWER SEATS 8N - 15
DRIVER SEAT SWITCH (Continued)

DIAGNOSIS AND TESTING - PASSENGER SEAT
SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 4). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
PASSENGER SEAT SWITCH TEST TABLE
PASSENGER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL DOWN A-E, A-M, B-N, B-E
VERTICAL UP A-J, A-N, B-M, B-E
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT DOWN A-M, B-N
FRONT TILT UP A-N, B-M
REAR TILT DOWN A-E, B-J
REAR TILT UP A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (DEFLATE) O-P, Q-R
LUMBAR DOWN
(INFLATE)O-R, P-Q
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the seat cushion side shield from the
seat. Refer to the Body section of the service manual
for the procedure.
(3) Pull the switch bezel or side shield unit out
from the seat far enough to access the switch wire
harness connector. Gently pry the locking tabs of the
switch away from the wire harness connector and
carefully unplug the connector from the power seat
switch module.
(4) Remove the screws that secure the power seat
switch.
INSTALLATION
(1) Position the power seat switch on the seat
cushion bezel and install the screws that secure the
power seat switch to seat cushion side bezel.
(2) Connect the electrical connector.
(3) Install the seat cushion switch bezel on the
seat. Refer to the Body section of the service manual
for the procedure.
(4) If equipped, install the screw that secures the
recliner lever to the recliner mechanism release shaft
on the outboard side of the front seat.
(5) Connect the battery negative cable.
POWER SEAT TRACK
DESCRIPTION
The eight-way power seat option includes a power
seat track assembly located under each front seat
(Fig. 5). The power seat track assembly replaces the
standard manually operated seat tracks. The lower
half of the power seat track is secured at the front
with two bolts to the floor panel seat cross member,
and at the rear with two bolts to the floor panel.
Four nuts secure the bottom of the seat cushion
frame to the upper half of the power seat track unit.
The power seat track assembly cannot be repaired,
and is serviced only as a complete assembly. If any
component in this assembly is faulty or damaged, the
entire power seat track must be replaced.
OPERATION
The power seat track unit includes three reversible
electric motors that are secured to the upper half of
the track unit. Each motor moves the seat adjuster
through a combination of worm-drive gearboxes and
screw-type drive units.
The front and rear of the seat are operated by two
separate vertical adjustment motors. These motors
can be operated independently of each other, tilting
the entire seat assembly forward or rearward; or,
Fig. 4 Testing Passenger Power Seat Switch
8N - 16 POWER SEATSDR
PASSENGER SEAT SWITCH (Continued)

they can be operated in unison by selecting the
proper power seat switch functions, which will raise
or lower the entire seat assembly. The third motor is
the horizontal adjustment motor, which moves the
seat track in the forward and rearward directions.
DIAGNOSIS AND TESTING - POWER SEAT
TRACK
For complete power seat circuit descriptions and
diagrams, refer to Wiring Diagrams.
Operate the power seat switch to move all three
seat motors in each direction. The seat should move
in each of the selected directions. If the power seat
track fails to operate in only one direction, move the
seat track a short distance in the opposite direction
and test again to be certain that the track is not at
its travel limit. If the power seat track still fails to
operate in only one direction, refer to Diagnosis and
Testing of the Power Seat Switch in this section. If
the power seat track fails to operate in more than
one direction, proceed as follows:
(1) Check the power seat fuse in the power distri-
bution center. If OK, go to Step 2. If not OK, replace
the faulty fuse.
(2) Remove the power seat switch from the seat.
Check for battery voltage at the fused B(+) circuit
cavity of the power seat switch wire harness connec-
tor. If OK, go to Step 3. If not OK, repair the open
circuit to the power distribution center as required.(3) Check for continuity between the ground cir-
cuit cavity of the power seat switch wire harness con-
nector and a good ground. There should be
continuity. If OK, go to Step 4. If not OK, repair the
open circuit to ground as required.
(4) Test the power seat switch as described in this
group. If the switch tests OK, check the wire harness
between the power seat switch and the motor for
shorts or opens. If the circuits check OK, replace the
faulty power seat track (adjuster) assembly. If the
circuits are not OK, repair the wire harness as
required.
REMOVAL
(1) Remove the appropriate seat from the vehicle.
(Refer to 23 - BODY/SEATS/SEAT - REMOVAL).
(2) Remove the power seat switch from the seat.
Refer to the procedure in this section of the service
manual.
(3) Remove four seat track mounting nuts from
cushion pan.
(4) Disconnect the power seat electrical and
remove the seat track from the seat cushion.
(5) Remove the necessary components that must
be transferred to the replacement seat track (seat
belt buckles, wire harness, etc.).
INSTALLATION
(1) Install the necessary components that must be
transferred to the replacement seat track (seat belt
buckles, wire harness, etc.).
(2) Position the seat track and install the retaining
nuts on the seat cushion pan studs. Torque the bolts
to 25 N´m.
(3) Route and connect the power seat electrical on
the seat track and cushion pan.
(4) Install the power seat switch on the seat. Refer
to the procedure in this section of the service man-
ual.
(5) Install the seat in the vehicle (Refer to 23 -
BODY/SEATS/SEAT - INSTALLATION).
(6) Connect the negative battery cable.
LUMBAR CONTROL SWITCH
DESCRIPTION
The power lumbar seat option includes an electri-
cally operated lumbar support mechanism. A single
two-way momentary power lumbar switch is integral
with the power seat switches. The power lumbar
switch is secured to the back of the seat cushion side
shield with screws, and the switch paddle protrudes
through a hole to the outside of the shield. The
switch paddle is located in a shallow depression
molded into the outer surface of the seat cushion side
Fig. 5 DR Driver Power Seat Track
1 - POWER SEAT TRACK ASSEMBLY
2 - SEAT TRACK WIRE HARNESS
3 - SEAT BELT BUCKLE ASSEMBLIES
DRPOWER SEATS 8N - 17
POWER SEAT TRACK (Continued)

shield that helps to shroud it from unintentional
actuation when entering or leaving the vehicle.
The power lumbar switches cannot be adjusted or
repaired and, if faulty or damaged, the seat switch
assembly must be replaced.
OPERATION
When the power lumbar switch paddle is actuated,
a battery feed and a ground path are applied through
the switch contacts to the power lumbar adjuster
motor. The motor operates to move the lumbar
adjuster through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the motor to run in the
opposite direction.
The power lumbar switch should not be held
applied in either direction after the adjuster has
reached its travel limit. The power lumbar adjuster
motor contains a self-resetting circuit breaker to pro-
tect it from overload. However, consecutive or fre-
quent resetting of the circuit breaker must not be
allowed to continue, or the motor may be damaged.
REMOVAL
The power lumbar switch is integral with the other
power seat switches. Refer to the appropriate driver
or passenger power front seat switch removal and/or
installation procedure.
LUMBAR MOTOR
DESCRIPTION
The power lumbar seat option includes an electri-
cally operated lumbar support mechanism. The only
visible evidence of this option is the separate power
lumbar switch control paddle that is located on the
outboard seat cushion switch bezel, next to the other
power seat switch control knobs. The power lumbar
adjuster and motor are concealed beneath the seat
back trim cover and padding, where they are secured
to a molded plastic back panel and to the seat back
frame.
The power lumbar adjuster cannot be repaired, and
is serviced only as a unit with the seat back frame. If
the power lumbar adjuster or the seat back frame
are damaged or faulty, the entire seat back frame
unit must be replaced (Refer to 23 - BODY/SEATS/
SEAT BACK - REMOVAL).
OPERATION
The power lumbar adjuster mechanism includes a
reversible electric motor that is secured to theinboard side of the seat back panel and is connected
to a worm-drive gearbox. The motor and gearbox
operate the lumbar adjuster mechanism in the center
of the seat back driving a nut up or down a fixed
drive screw. The action of this nut extends or con-
tracts the plastic lumbar support band. The more
this band is contracted, the more outward pressure is
applied against the center of the seat back padding,
providing additional lumbar support.
DIAGNOSIS AND TESTING - LUMBAR MOTOR
Actuate the power lumbar switch to move the
power lumbar adjuster in each direction. The power
lumbar adjuster should move in both directions. It
should be noted that the power lumber adjuster nor-
mally operates very quietly and exhibits little visible
movement. If the power lumbar adjuster fails to oper-
ate in only one direction, move the adjuster a short
distance in the opposite direction and test again to be
certain that the adjuster is not at its travel limit. If
the power lumbar adjuster fails to operate in only
one direction, Test the appropriate power seat switch
as described in this group. If the power lumbar
adjuster fails to operate in either direction, perform
the following tests. For complete circuit diagrams,
refer toWiring.
(1) Check the power seat circuit breaker. If OK, go
to Step 2. If not OK, replace the faulty power seat
circuit breaker.
(2) Check for battery voltage at the power seat cir-
cuit breaker. If OK, go to Step 3. If not OK, repair
the open fused B(+) circuit to the fuse in the Inte-
grated Power Module as required.
(3) Remove the outboard seat cushion side shield
from the seat. Disconnect the seat wire harness con-
nector from the power lumbar switch connector
receptacle. Check for battery voltage at the fused
B(+) circuit cavity of the power seat wire harness
connector for the power lumbar switch. If OK, go to
Step 4. If not OK, repair the open fused B(+) circuit
to the power seat as required.
(4) Check for continuity between the ground cir-
cuit cavity of the power seat wire harness connector
for the power lumbar switch and a good ground.
There should be continuity. If OK, go to Step 5. If not
OK, repair the open ground circuit to ground as
required.
(5) Test the power lumbar switch. . If the switch
tests OK, test the circuits of the power seat wire har-
ness between the power lumbar adjuster motor and
the power lumbar switch for shorts or opens. If the
circuits check OK, replace the faulty seat back frame
assembly. If the circuits are not OK, repair the power
seat wire harness as required.
8N - 18 POWER SEATSDR
LUMBAR CONTROL SWITCH (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
REAR WHEEL ANTILOCK BRAKES....... 8W-34-1
ALL WHEEL ANTILOCK BRAKES........ 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING.................. 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
NAVIGATION/TELECOMMUNICATION..... 8W-55-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUTS............... 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 DRWIRING 8W - 1

8W-63 POWER SEATS
Component Page
Fuse 7............................ 8W-63-2
Fuse 48............................ 8W-63-6
G202.............................. 8W-63-5
G301.............................. 8W-63-7
G302.......................... 8W-63-2, 3, 4
Heated Seat Cushion-Driver............ 8W-63-7
Heated Seat Cushion-Passenger......... 8W-63-7
Heated Seat Switch-Driver........... 8W-63-5, 6
Heated Seat Switch-Passenger........ 8W-63-5, 6
Instrument Cluster................... 8W-63-5
Integrated Power Module............ 8W-63-2, 6
Lumbar Motor-Driver................. 8W-63-2
Lumbar Motor-Passenger............ 8W-63-3, 4Component Page
Passenger Lumbar Switch............. 8W-63-3
Power Seat Motor-Driver Front Vertical . . . 8W-63-2
Power Seat Motor-Driver Horizontal..... 8W-63-2
Power Seat Motor-Driver Rear Vertical . . . 8W-63-2
Power Seat Motor-Passenger Front
Vertical.......................... 8W-63-4
Power Seat Motor-Passenger Horizontal . . 8W-63-4
Power Seat Motor-Passenger Rear
Vertical.......................... 8W-63-4
Power Seat Switch-Driver............. 8W-63-2
Power Seat Switch-Passenger........... 8W-63-4
Seat Heater Interface Module......... 8W-63-6, 7
DR8W-63 POWER SEATS 8W - 63 - 1