1998 DODGE RAM 1500 oil

ment of the vehicle. The front fog lamp relay is a
conventional International Standards Organization
(ISO) micro relay (Fig. 9). Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The relay is contained within a small, rect-
angular, 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 bot-
tom of the relay base.
The front fog lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The front fog lamp relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put to the front fog lamps. 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 front fog lamp 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 front fog lamp relay
include:
²Common Feed Terminal- The common feed
terminal (30) receives battery voltage at all times
from a fuse in the PDC through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a front fog lamp relay
control circuit. The FCM controls front fog lamp oper-
ation by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery voltage at all times from
a fuse in the PDC through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the front fog lamps
through a front fog lamp relay output circuit and
provides battery voltage to the front fog lamps when-
ever the relay is energized.²Normally Closed Terminal- The normally
closed terminal (87A) is not connected in this appli-
cation.
The front fog lamp relay can be diagnosed using
conventional diagnostic tools and methods. Refer to
the appropriate wiring information for diagnosis and
testing of the front fog lamp micro-relay and for com-
plete wiring diagrams.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover for the Power Distribution
Center (PDC).
(3) Remove the front fog lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
DRLAMPS/LIGHTING - EXTERIOR 8L - 13
FOG LAMP RELAY (Continued)

(1) Position the front fog lamp relay to the proper
receptacle in the Power Distribution Center (PDC).
(2) Align the front fog lamp relay terminals with
the terminal cavities in the PDC.
(3) Press firmly and evenly on the top of the front
fog lamp relay until the terminals are fully seated in
the PDC.
(4) Reconnect the battery negative cable.
HAZARD SWITCH
DESCRIPTION
The hazard switch is activated by a push button
located in the multifunction switch on the top of the
steering column between the steering wheel and
instrument cluster.
The hazard warning system allows the vehicle
operator to provide other vehicle operators in the
near proximity an optical indication that the vehicle
is disabled or an obstacle to traffic flow. The hazard
warning system has battery voltage at all times,
regardless of ignition position.
OPERATION
The instrument cluster monitors the multiplexed
multifunction switch operation. When the hazard
warning switch is activated, the instrument cluster
will send a J1850 bus message to the Front Control
Module (FCM), then activate the two turn signal
indicators and audible click in the instrument clus-
ter.
The FCM will then activate the necessary relays in
the Power Distribution Center (PDC) to begin flash-
ing both the front and rear turn signal indicator
lamps.
HEADLAMP
REMOVAL
(1) Disconnect and isolate the negitive battery
cable.
(2) Remove the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - REMOVAL).
(3) Seperate the socket from the headlamp unit.
INSTALLATION
CAUTION: Do Not Touch the bulb glass with fingers
or other oily surfaces. Reduced bulb life will result.
(1) Install the socket into the headlamp unit.
(2) Install the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - INSTALLATION).(3) Connect the negitive battery cable.
HEADLAMP SWITCH
DESCRIPTION
The multiplexed headlamp switch is located on the
instrument panel. The headlamp switch controls the
parking lamps, fog lamps and the headlamps. A sep-
arate switch in the module controls the interior
lamps and instrument cluster illumination. This
switch also contains a rheostat for controlling the
illumination level of the cluster lamps.
OPERATION
The multiplexed headlamp switch has an off, park-
ing lamp, fog lamp and a headlamp on position. High
beams are controlled by the multiplexed multifunc-
tion switch on the steering column. The fog lamps
are illuminated by pulling back on the headlamp
switch knob when in the parking lamp or headlamp
ON position.The headlamp switch cannot be
repaired. It must be replaced.
The Instrument Cluster monitors the headlamp
and multifunction switch operation. When the head-
lamp switch is rotated to the parking lamp or On
position the Instrument Cluster sends a J1850 mes-
sage to the Front Control Module, which is mated to
the power distribution center to become the Inte-
grated Control Module, to illuminate the appropriate
bulbs. When the multifunction switch is activated to
the optical horn or high beam position the Instru-
ment Cluster illuminates the high beam indicator
and sends a J1850 message to the Front Control
Module to illuminate the appropriate bulbs.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
8L - 14 LAMPS/LIGHTING - EXTERIORDR
FOG LAMP RELAY (Continued)

(2) Remove the left instrument panel bezel. (Refer
to 23 - BODY/INSTRUMENT PANEL/CLUSTER
BEZEL - REMOVAL).
(3) Disconnect the harness connector.
(4) Remove the screws that secure the headlamp
switch to the instrument panel bezel (Fig. 10).
(5) Remove the headlamp switch from the instru-
ment panel bezel.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the headlamp switch to the left instru-
ment panel bezal and secure with screws.Tighten the
screws to 2.2 N´m (20 in. lbs.).(2) Reconnect the instrument panel wire harness
connector for the headlamp switch.
(3) Position the left instrument panel bezal on to
the instrument panel.
(4) Install the cluster bezel onto the instrument
panel (Fig. 10).
(5) Connect the battery negative cable.
HEADLAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the push pins attaching the seal to the
fender.
(3) Remove the bolts attaching the headlamp unit
to the fender (Fig. 11).
(4) Remove the bulb sockets from the headlamp
unit
(5) Separate headlamp unit from vehicle.
INSTALLATION
CAUTION: Do not touch the bulb glass with fingers
or other oily surfaces. Reduced bulb life will result.
(1) Install the bulb sockets for the front park/turn
signal and headlamp.
(2) Position headlamp unit in inner fender panel.
Fig. 10 Headlamp Switch Removal
1 - DASH BOARD
2 - HEADLAMP SWITCH
3 - INSTRUMENT PANEL BEZAL
Fig. 11 Headlamp - Typical
1 - SEAL
2 - PUSH PIN
3 - SCREW
4 - HEADLAMP UNIT
DRLAMPS/LIGHTING - EXTERIOR 8L - 15
HEADLAMP SWITCH (Continued)

PARK LAMP RELAY
DESCRIPTION
The park lamp relay is located in the Power Dis-
tribution Center (PDC) of the vehicle. The park lamp
relay is a conventional International Standards
Organization (ISO) micro relay (Fig. 17). Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminal
patterns, and terminal functions.
The park lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The park lamp relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put to the park lamps. 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 park lamp relay terminals are connected to
the vehicle electrical system through a connector in
the Junction Block (JB). The inputs and outputs of
the headlamp low beam relay include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the park lamps through
the park lamp relay output circuit and provides
ground to the park lamps when the relay is de-ener-
gized, and battery current to the park lamps when-
ever the relay is energized.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a park lamp relay
control circuit. The FCM controls park lamp opera-
tion by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the PDC through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) receives battery current at all times
from a fuse in the Power Distribution Center (PDC)
through a fused B(+) circuit.
²Normally Closed Terminal- The normally
closed terminal (87A) is connected to ground at all
times.
The park lamp relay can be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - PARK LAMP
RELAY
The park lamp relay (Fig. 18) is located in the
Power Distribution Center (PDC). Refer to the appro-
priate wiring information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Remove the park lamp relay from the PDC.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
Fig. 17 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8L - 20 LAMPS/LIGHTING - EXTERIORDR

no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.(2) Remove the Power Distribution Center (PDC)
cover.
(3) Remove the park lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the park lamp relay to the proper
receptacle in the Power Distribution Center (PDC).
(2) Align the park lamp relay terminals with the
terminal cavities in the PDC.
(3) Press firmly and evenly on the top of the park
lamp relay until the terminals are fully seated in the
PDC.
(4) Install the PDC cover.
(5) Reconnect the battery negative cable.
PARK/TURN SIGNAL LAMP
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the headlamp unit.(Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - REMOVAL).
(3) Remove the bulb socket from the headlamp
unit.
(4) Release the front park/turn signal bulb locking
tabs and remove the bulb from the socket (Fig. 19).
INSTALLATION
(1) Install the front park/turn signal bulb into the
bulb socket.
(2) Install the bulb socket into the headlamp unit.
(3) Install the headlamp unit (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/HEAD-
LAMP UNIT - INSTALLATION).
Fig. 18 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DRLAMPS/LIGHTING - EXTERIOR 8L - 21
PARK LAMP RELAY (Continued)

INSTALLATION
(1) Install remote keyless entry module to instru-
ment cluster.
(2) Install instrument cluster (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - INSTALLA-
TION).
(3) Connect the battery negative cable.
REMOTE KEYLESS ENTRY
TRANSMITTER
DIAGNOSIS AND TESTING - REMOTE KEYLESS
ENTRY TRANSMITTER
Using special tool 9001, first test to ensure that
the transmitter is functioning. Typical testing dis-
tance is 2.5 centimeters (1 inch) for Asian transmit-
ters and 30.5 centimeters (12 inches) for all others.
To test, position the transmitter as shown (Fig. 5).
Press any transmitter button, then test each button
individually. The tool will beep if a radio signal
strength that lights five or more LED's is detected.
Repeat this test three times. If transmitter fails any
of the test refer to the Diagnostic Procedures man-
ual.
STANDARD PROCEDURE
STANDARD PROCEDURE - RKE TRANSMITTER
BATTERIES
NOTE: Do not disturb the metal terminal near the
batteries. Avoid touching the new batteries. Skin
oils may cause battery deterioration. If batteries are
touched, clean with rubbing alcohol.The Remote Keyless Entry (RKE) transmitter case
snaps open and shut for battery access. To replace
the RKE transmitter batteries:
(1) Using a thin coin, gently pry at the notch in
the center seam of the RKE transmitter case halves
near the key ring until the two halves unsnap. Be
careful not to damage the rubber gasket when sepa-
rating the case halves.
(2) Lift the back half of the transmitter case off of
the RKE transmitter.
(3) Remove the two batteries from the RKE trans-
mitter.
(4) Replace the two batteries with new 3V lithium
2016 cell. Install the batteries with the positive ter-
minal up. Reference the ª+ SIDE UPº on the inside of
the bottom half of the transmitter case.
(5) Align the two RKE transmitter case halves
with each other, and squeeze them firmly and evenly
together until they snap back into place. Test trans-
mitter operation.
STANDARD PROCEDURE - RKE TRANSMITTER
CUSTOMER PREFERENCES
AUTOMATIC (ROLLING) LOCKS
The rolling locks feature can be toggled ON/OFF
by using the DRB IIItonly.
HORN CHIRP DISABLING / ENABLING
The horn chirp can be toggled using a DRB IIItor
by using the Remote Keyless Entry (RKE) transmit-
ter that is already programmed to the vehicle.
To DISABLE (cancel) the horn chirp feature:
(1) Enter the vehicle and close all doors.
(2) Fasten the seat belt (this will cancel the seat
belt chime).
(3) Turn the ignition to the ON position.
(4) Press and hold the LOCK button for 4 seconds.
Within 6 seconds with the LOCK button still
depressed, press the UNLOCK button. When a single
chime is heard, release both buttons.
(5) Turn the ignition OFF.
(6) Turn the ignition ON or wait 60 seconds.
(7) Test the horn chirp feature by pressing the
LOCK button.
If a chime is not heard, program mode was can-
celed before the feature could be disabled. If neces-
sary, repeat the procedure.
To ENABLE the horn chirp feature, repeat the
above procedure.
OPTICAL CHIRP (FLASH) DISABLING / ENABLING
The optical chirp can be toggled using a DRB IIIt
or by using the Remote Keyless Entry (RKE) trans-
mitter that is already programmed to the vehicle.
To DISABLE (cancel) the optical chirp feature:
Fig. 5 TRANSMITTER DIAGNOSIS
8N - 8 POWER LOCKSDR
REMOTE KEYLESS ENTRY MODULE (Continued)

OPERATION
The seat belt tension reducer is controlled by a
ground signal received from the seat belt switch on
the seat belt switch sense circuit and a battery cur-
rent signal received from the ignition switch on the
fused ignition switch output (run-accessory) circuit.
When the seat belt switch is closed (the driver side
front seat belt is fastened) and the ignition switch is
in the On or Accessory positions, the seat belt tension
reducer solenoid is energized. When the solenoid is
energized, it actuates a mechanism within the driver
side front outboard seat belt retractor to reduce the
normal recoil spring tension exerted by the retractor
spool, which is designed to reel in the seat belt web-
bing onto the spool. When the driver side seat belt is
unbuckled or if the ignition switch is turned to any
position except On or Accessory, the tension reducer
solenoid is de-energized and the normal recoil spring
tension of the retractor is restored.
The action of the seat belt tension reducer results
in improved seat belt comfort for the driver. Reducing
the seat belt retractor recoil spring tension is desir-
able on standard cab models of this vehicle and not
on the quad cab model due to the different mounting
position required for the seat belt turning loop on the
B-pillar relative to the driver's seat position on the
standard cab model. The seat belt tension reducer
may be diagnosed using conventional diagnostic tools
and methods.
DIAGNOSIS AND TESTING - SEAT BELT
TENSION REDUCER
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the seat belt tension reducer from the tension
reducer connector receptacle on the driver side front
outboard seat belt and retractor unit. Using an ohm-
meter, measure the resistance between the seat belt
switch sense circuit terminal pin and the fused igni-
tion switch output (run-accessory) circuit terminal
pin in the tension reducer connector receptacle on
the retractor. Resistance through the tension reducer
solenoid coil should be 53 ohms at 20É C (68É F). If
OK, go to Step 2. If not OK, replace the faulty driver
side front outboard seat belt and retractor unit.
(2) Check for continuity between the seat belt
switch sense circuit cavity of the body wire harness
connector for the seat belt tension reducer and a good
ground. There should be continuity with the driver
side front seat belt buckled, and no continuity with
the driver side front seat belt unbuckled. If OK, go to
Step 3. If not OK, repair the shorted or open seat
belt switch sense circuit between the tension reducer
and the seat belt switch as required.
(3) Reconnect the battery negative cable. Check for
battery current at the fused ignition switch output
(run-accessory) circuit of the body wire harness con-
nector for the seat belt tension reducer. There should
be battery current with the ignition switch in the On
or Accessory positions, and no battery current with
the ignition switch in any other position. If not OK,
repair the shorted or open fused ignition switch out-
put (run-accessory) circuit between the tension
reducer and the ignition switch as required.
8O - 54 RESTRAINTSDR
SEAT BELT TENSION REDUCER (Continued)

INSTALLATION
NOTE: The notched end of the wiper element flexor
should always be oriented towards the end of the
wiper blade that is nearest to the wiper pivot.
(1) Lift the wiper arm off of the windshield glass,
until the wiper arm hinge is in its over-center posi-
tion.
(2) Position the wiper blade near the hook forma-
tion on the tip of the arm with the notched end of the
wiper element flexor oriented towards the end of the
wiper arm that is nearest to the wiper pivot.
(3) Insert the hook formation on the tip of the
wiper arm through the opening in the wiper blade
superstructure ahead of the wiper blade pivot block/
latch unit far enough to engage the pivot block into
the hook (Fig. 21).
(4) Slide the wiper blade pivot block/latch up into
the hook formation on the tip of the wiper arm until
the latch release tab snaps into its locked position.
Latch engagement will be accompanied by an audible
click.
(5) Gently lower the wiper blade onto the glass.
WIPER HIGH/LOW RELAY
DESCRIPTION
The wiper high/low relay is located in the Inte-
grated Power Module (IPM) in the engine compart-
ment near the battery. The wiper high/low relay is a
conventional International Standards Organization
(ISO) micro relay (Fig. 22). Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The relay is contained within a small, rect-
angular, molded plastic housing and is connected to
all of the required inputs and outputs by five integralmale spade-type terminals that extend from the bot-
tom of the relay base.
The wiper high/low relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper high/low relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put 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 high/low relay terminals are connected
to the vehicle electrical system through a connector
receptacle in the Integrated Power Module (IPM).
The inputs and outputs of the wiper high/low relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the output of the wiper
on/off relay at all times through the wiper on/off
relay output circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a wiper high/low
relay control circuit. The FCM controls wiper motor
operation by controlling a ground path through this
circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current when the ignition
switch is in the On or Accessory positions from a fuse
in the Integrated Power Module (IPM) through a
fused ignition switch output (run-acc) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the high speed brush of
the wiper motor through a wiper high/low relay high
speed output circuit, and is connected to the high
speed brush whenever the relay is energized.
²Normally Closed Terminal- The normally
closed terminal (87A) is connected to the low speed
brush of the wiper motor through a wiper high/low
relay low speed output circuit, and is connected to
the low speed brush whenever the relay is de-ener-
gized.
Fig. 22 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8R - 20 WIPERS/WASHERSDR
WIPER BLADE (Continued)