2002 JEEP LIBERTY Wiring

(7) Pull the bulb straight out of the license plate
lamp unit socket.
INSTALLATION
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
NORTH AMERICA
(1) Align the base of the bulb with the receptacle
in the license plate lamp unit socket.
(2) Push the bulb straight into the license plate
lamp unit socket until it is firmly seated.
(3) Reach through the opening in the rear bumper
fascia between the license plate and the lamp to
align the socket and bulb with the socket opening on
the back of the lamp unit housing (Fig. 45).
(4) Push the socket and bulb straight into the
license plate lamp unit housing until it is firmly
seated.
(5) Reconnect the battery negative cable.
REST-OF-WORLD
(1) Align the base of the bulb with the receptacle
in the license plate lamp unit socket.
(2) Push the bulb straight into the license plate
lamp unit socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing on the top of the license plate lamp unit housing
(Fig. 47).(4) Push the socket and bulb straight into the
license plate lamp unit housing until it is firmly
seated.
(5) Rotate the socket on the top of the license plate
lamp unit housing clockwise about 30 degrees.
(6) Swing the license plate bracket back against
the spare tire (Fig. 46).
(7) Lift up the bottom of the license mounting
plate far enough to install and tighten the two
screws that secure the license plate bracket to the
special lug nuts on the spare tire. Tighten the screws
to 28 N´m (21 ft. lbs.).
(8) Lower the bottom of the license mounting plate
and, using hand pressure, snap it into place on the
license plate bracket.
(9) Reconnect the battery negative cable.
LICENSE PLATE LAMP UNIT
REMOVAL
NORTH AMERICA
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two screws that secure the license
plate lamp unit to the rear bumper fascia (Fig. 48).
(3) Pull the license plate lamp unit down and out
through the mounting hole in the rear bumper fascia
far enough to access and disconnect the wire harness
connector for the lamp socket pigtail wire.
(4) Remove the license plate lamp unit from the
rear bumper fascia.
Fig. 47 License Plate Lamp Bulb Remove/Install -
Rest-Of-World
1 - LAMP UNIT (2)
2 - LICENSE PLATE BRACKET
3 - SCREW (4)
4 - BULB & SOCKET (2)
Fig. 48 License Plate Lamp Unit Remove/Install
1 - REAR BUMPER FASCIA
2 - LICENSE PLATE LAMP UNIT
3 - SCREW (2)
KJLAMPS/LIGHTING - EXTERIOR 8L - 45
LICENSE PLATE LAMP BULB (Continued)

tor as the steering wheel rotates to the right and
returns to center, which will cancel the turn signal
event and release the control stalk from the detent so
it returns to the neutral Off position. When a turn
signal is activated, the multi-function switch provides
a ground output on a right or left turn switch sense
circuit to the combination flasher circuitry within the
hazard switch, and the combination flasher flashes
the turn signal lamps.
RIGHT CONTROL STALK The right (wiper) con-
trol stalk of the multi-function switch operates as fol-
lows:
²Continuous Front Wipe Modes- The control
knob on the end of the multi-function switch right
(wiper) control stalk is rotated to an intermediate
detent that is one detent rearward (counterclockwise)
from the full forward (clockwise) detent to select the
low speed continuous front wiper mode, or to its full
forward (clockwise) detent to select the high speed
continuous front wiper mode. The multi-function
switch provides a resistor multiplexed output to the
Body Control Module (BCM) on a front wiper switch
mux circuit, and the BCM responds by energizing the
wiper on/off relay in the Power Distribution Center
(PDC) for the front low speed continuous wipe mode,
or the wiper on/off relay and the wiper high/low relay
in the PDC for the front high speed continuous wipe
mode as required.
²Continuous Rear Wipe Mode- The control
ring on the multi-function switch right (wiper) con-
trol stalk is rotated to the most forward (clockwise)
detent to select the continuous rear wiper mode. The
multi-function switch provides a battery current out-
put to the rear wiper motor on a rear wiper on driver
circuit to signal the rear wiper motor to operate in
the continuous wipe mode.
²Front Washer Mode- The right (wiper) control
stalk of the multi-function switch is pulled towards
the steering wheel to momentarily activate the
washer pump in the front washer mode. The washer
pump will continue to operate in the front washer
mode until the control stalk is released. The multi-
function switch provides a ground output on a
washer pump sense circuit, and battery current on a
washer pump driver circuit to energize the washer
pump in the front washer mode.
²Front Wiper Mist Mode- The right (wiper)
control stalk of the multi-function switch is pushed
towards the floor to momentarily activate the front
wiper motor in the mist mode. The front wiper motor
will continue to operate in the mist mode until the
control stalk is released. The multi-function switch
provides a resistor multiplexed output to the Body
Control Module (BCM) on a front wiper switch mux
circuit, and the BCM responds by energizing the
wiper on/off relay in the Power Distribution Center(PDC) to operate the front wiper motor momentarily
at low speed to provide the front wiper mist mode.
²Intermittent Front Wipe Mode- The control
knob on the end of the multi-function switch right
(wiper) control stalk is rotated to one of five minor
intermediate detents to select the desired intermit-
tent front wipe delay interval. The control knob is
rotated rearward (counterclockwise) to increase the
delay, or forward (clockwise) to decrease the delay.
The multi-function switch provides a resistor multi-
plexed output to the Body Control Module (BCM) on
a front wiper switch mux circuit, and the BCM
responds by energizing the wiper on/off relay in the
Power Distribution Center (PDC) to operate the front
wiper motor at the selected delay intervals.
²Intermittent Rear Wipe Mode- The control
ring on the multi-function switch right (wiper) con-
trol stalk is rotated to the center detent to select the
intermittent rear wiper mode. The multi-function
switch provides a battery current output to the rear
wiper motor on a rear wiper intermittent driver cir-
cuit to signal the rear wiper motor to operate in the
intermittent wipe mode.
²Rear Washer Mode- The control ring on the
multi-function switch right (wiper) control stalk is
rotated to either the full forward (clockwise) or full
rearward (counterclockwise) momentary positions to
activate the washer pump in the rear washer mode.
The washer pump will continue to operate in the rear
washer mode until the control ring is released. The
multi-function switch provides a ground output on a
washer pump driver circuit, and battery current on a
washer pump sense circuit to energize the washer
pump in the rear washer mode.
DIAGNOSIS AND TESTING - MULTI-FUNCTION
SWITCH
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.
8L - 50 LAMPS/LIGHTING - EXTERIORKJ
MULTI-FUNCTION SWITCH (Continued)

driver side instrument panel end bracket near the
Junction Block (JB).
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. 54) is located in the
Junction Block (JB) under the driver side outboard
end of the instrument panel. 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: 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 JB.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/PARK LAMP RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
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 steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the park lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the Junction Block (JB) (Fig. 55).
Fig. 54 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS/LIGHTING - EXTERIOR 8L - 55
PARK LAMP RELAY (Continued)

OPERATION
The rear fog lamp relay is an electromechanical
switch that uses a low current input from the Body
Control Module (BCM) to control a high current out-
put to the rear 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 rear fog lamp relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Junction Block (JB). The inputs and
outputs of the rear fog lamp relay include:
²Common Feed Terminal- The common feed
terminal (30) receives battery current at all times
from a fuse in the JB through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the pre-
mium Body Control Module (BCM) through a rear
fog lamp relay control circuit. The BCM controls rear
fog lamp operation by controlling a ground path
through this circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the JB through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the rear fog lamps
through a rear fog lamp relay output circuit and pro-
vides battery current to the rear fog lamps whenever
the relay is energized.
²Normally Closed Terminal- The normally
closed terminal (87A) is not connected in this appli-
cation.
The rear fog lamp relay can be diagnosed using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - REAR FOG LAMP
RELAY
The rear fog lamp relay (Fig. 57) is located in the
Junction Block (JB) under the driver side outboard
end of the instrument panel. 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 locationviews for the various wire harness connectors, splices
and grounds.
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 rear fog lamp relay from the JB.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/REAR FOG LAMP RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
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
Fig. 57 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS/LIGHTING - EXTERIOR 8L - 57
REAR FOG LAMP RELAY (Continued)

Be certain any removed bulb is replaced with the
same bulb size and type that was removed.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear lamp unit from the end of the
quarter panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REAR LAMP UNIT -
REMOVAL).
(3) Firmly grasp the socket on the socket plate at
the back of the rear lamp unit housing for the bulb
that is being removed (Fig. 59).
(4) Rotate the socket on the socket plate at the
back of the rear lamp unit housing counterclockwise
about 30 degrees.
(5) Pull the socket and bulb straight out of the
back of the rear lamp unit housing.
(6) Pull the bulb straight out of the rear lamp unit
socket.
INSTALLATION
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
(1) Align the base of the bulb with the receptacle
in the rear lamp unit socket.
(2) Push the bulb straight into the rear lamp unit
socket until it is firmly seated.
(3) Align the socket and bulb with the opening in
the socket plate on the back of the rear lamp unit
housing (Fig. 59).(4) Push the socket and bulb straight into the rear
lamp unit housing until the socket is firmly seated
against the socket plate.
(5) Rotate the socket on the socket plate at the
back of the rear lamp unit housing clockwise about
30 degrees.
(6) Reinstall the rear lamp unit onto the end of the
quarter panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REAR LAMP UNIT -
INSTALLATION).
(7) Reconnect the battery negative cable.
REAR LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Open the tailgate to access and remove the two
screws that secure the inboard side of the rear lamp
unit to the side jamb of the tailgate opening (Fig. 60).
(3) Pull the outboard side of the rear lamp unit
rearward (away from the end of the quarter panel)
far enough to unsnap the two ball studs on the out-
board side of the lamp housing from the plastic nuts
in the quarter panel.
(4) Pull the rear lamp unit away from the quarter
panel far enough to access and disconnect the wire
harness connector for the lamp unit from the connec-
tor receptacle on the lamp socket plate.
(5) Remove the rear lamp unit from the quarter
panel.
Fig. 59 Rear Lamp Bulb Remove/Install
1 - REAR LAMP HOUSING
2 - BULB HOLDER
3 - BULB
4 - SOCKET PLATE
Fig. 60 Rear Lamp Unit Remove/Install
1 - PLASTIC NUT (2)
2 - WIRE HARNESS CONNECTOR
3 - PLASTIC NUT (2)
4 - REAR LAMP UNIT
5 - SCREW (2)
KJLAMPS/LIGHTING - EXTERIOR 8L - 59
REAR LAMP BULB (Continued)

(6) Remove the plastic nuts from the quarter panel
and discard.
INSTALLATION
(1) Install new plastic nuts into the quarter panel
(Fig. 60).
(2) Position the rear lamp unit to the quarter
panel.
(3) Reconnect the wire harness connector for the
rear lamp unit to the connector receptacle on the
lamp socket plate.
(4) Align the two ball studs on the outboard side of
the rear lamp unit housing with the plastic nuts in
the quarter panel.
(5) Using hand pressure, push the outboard side of
the rear lamp unit forward (towards the end of the
quarter panel) far enough to snap the two ball studs
on the outboard side of the lamp housing into the
plastic nuts in the quarter panel.
(6) Align the mounting holes on the inboard side of
the rear lamp unit housing with the plastic nuts in
the side jamb of the tailgate opening.
(7) Install and tighten the two screws that secure
the inboard side of the rear lamp unit housing to the
plastic nuts in the side jamb of the tailgate opening.
Tighten the screws to 2 N´m (20 in. lbs.).
(8) Reconnect the battery negative cable.
REPEATER LAMP BULB
REMOVAL
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the repeater lamp unit from the front
fender panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REPEATER LAMP UNIT -
REMOVAL).
(3) Rotate the repeater lamp socket in the lamp
lens counterclockwise about 30 degrees (Fig. 61).
(4) Pull the socket and bulb straight out of the
repeater lamp lens.
(5) Pull the bulb straight out of the repeater lamp
socket.
INSTALLATION
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or typemay overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
(1) Align the base of the bulb with the receptacle
in the repeater lamp socket.
(2) Push the bulb straight into the repeater lamp
socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing in the repeater lamp lens (Fig. 61).
(4) Push the socket and bulb straight into the
repeater lamp lens until it is firmly seated
(5) Rotate the repeater lamp socket in the lamp
lens clockwise about 30 degrees.
(6) Reinstall the repeater lamp unit onto the front
fender panel. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/REPEATER LAMP UNIT -
INSTALLATION).
(7) Reconnect the battery negative cable.
REPEATER LAMP UNIT
REMOVAL
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Disconnect and isolate the battery negative
cable.
(2) Using a trim stick or another suitable wide
flat-bladed tool, carefully pry at the clearance notch
in the lower edge of the repeater lamp lens to disen-
gage the snap features of the lens from the mounting
hole in the front fender panel (Fig. 62).
(3) Pull the repeater lamp unit out from the front
fender panel far enough to access and disconnect the
Fig. 61 Repeater Lamp Bulb Remove/Install
1 - FRONT FENDER
2 - SOCKET
3 - BULB
4 - LENS
8L - 60 LAMPS/LIGHTING - EXTERIORKJ
REAR LAMP UNIT (Continued)

repeater lamp wire harness connector from the con-
nector receptacle on the back of the repeater lamp
unit socket.
(4) Remove the repeater lamp unit from the front
fender panel.
INSTALLATION
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Position the repeater lamp unit to the front
fender panel (Fig. 62).
(2) Reconnect the repeater lamp wire harness con-
nector to the connector receptacle on the back of the
repeater lamp unit socket.
(3) Position the repeater lamp unit into the mount-
ing hole in the front fender panel. Be certain that the
clearance notch on the edge of the repeater lamp lens
is oriented toward the bottom.
(4) Using hand pressure, press on the repeater
lamp unit firmly and evenly until the snap features
of the lens are fully engaged in the mounting hole of
the front fender panel.
(5) Reconnect the battery negative cable.
TRAILER TOW CONNECTOR
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the four screws that secure the trailer
tow connector to the bracket on the trailer hitch
receiver (Fig. 63).(3) Pull the trailer tow connector rearward from
the bracket on the trailer hitch receiver far enough to
access and disconnect the rear body wire harness
connector from the receptacle on the back of the
trailer tow connector.
(4) Remove the trailer tow connector from the
trailer hitch receiver.
INSTALLATION
(1) Position the trailer tow connector to the trailer
hitch receiver (Fig. 63).
(2) Reconnect the rear body wire harness connec-
tor to the receptacle on the back of the trailer tow
connector.
(3) Position the trailer tow connector into the
bracket on the trailer hitch receiver.
(4) Install and tighten the four screws that secure
the trailer tow connector to the bracket on the trailer
hitch receiver. Tighten the screws to 4 N´m (35 in.
lbs.).
(5) Reconnect the battery negative cable.
TRAILER TOW RELAY
DESCRIPTION
The trailer tow relays are located in a connector
bank above the right rear wheelhouse and behind the
quarter trim panel on vehicles equipped with the
optional factory-installed trailer towing package.
Four individual relays are used, one each for fused
ignition switch output (run), brake lamps, right turn
signal, and left turn signal outputs to a trailer
through the rear body wiring and connectors. The
trailer tow relays are conventional International
Standards Organization (ISO) micro relays (Fig. 64).
Fig. 62 Repeater Lamp Unit Remove/Install
1 - REPEATER LAMP UNIT
2 - FRONT FENDER PANEL
3 - INNER FENDER
4 - FRONT FASCIA WIRE HARNESS
Fig. 63 Trailer Tow Connector Remove/Install
1 - HITCH RECEIVER
2 - 7-WAY TRAILER TOW CONNECTOR
3 - SCREW (4)
4 - BRACKET
5 - WIRE HARNESS CONNECTOR
KJLAMPS/LIGHTING - EXTERIOR 8L - 61
REPEATER LAMP UNIT (Continued)

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 termi-
nals that extend from the bottom of the relay base.
The trailer tow relays cannot be adjusted or
repaired and, if faulty or damaged, the inoperative
relay must be replaced.
OPERATION
The trailer tow relays are electromechanical
switches. The relays each use an input from the cir-
cuit that they isolate from the trailer wiring to con-
trol a high current output to the trailer. 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 electro-
magnetic 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 terminals of each trailer tow relay are con-
nected to the vehicle electrical system through a con-nector bank in the rear lighting wire harness above
the right rear wheelhouse. 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. The trailer tow relays can be diagnosed
using conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - TRAILER TOW
RELAY
The trailer tow relays (Fig. 65) are located in a
connector bank above the right rear wheelhouse.
Refer to the appropriate wiring information. The wir-
ing 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: 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 trailer tow relay from the connec-
tor bank. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/TRAILER TOW RELAY -
REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
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, test the input and output circuits of
the relay. Refer to the appropriate wiring informa-
tion.
Fig. 64 Trailer Tow Relays
1 - RELAY CONNECTOR BANK
2 - REAR BODY WIRE HARNESS
3 - LEFT TURN RELAY
4 - RIGHT TURN RELAY
5 - BRAKE LAMP RELAY
6 - FUSED IGNITION SWITCH OUTPUT (RUN) RELAY
8L - 62 LAMPS/LIGHTING - EXTERIORKJ
TRAILER TOW RELAY (Continued)