ignition diagram JEEP GRAND CHEROKEE 2002 WJ / 2.G Service Manual

STANDARD PROCEDURE - TESTING OF
VOLTAGE POTENTIAL
(1) Connect the ground lead of a voltmeter to a
known good ground (Fig. 7).
(2) Connect the other lead of the voltmeter to the
selected test point. The vehicle ignition may need to
be turned ON to check voltage. Refer to the appropri-
ate test procedure.
STANDARD PROCEDURE - TESTING FOR
CONTINUITY
(1) Remove the fuse for the circuit being checked
or, disconnect the battery.
(2) Connect one lead of the ohmmeter to one side
of the circuit being tested (Fig. 8).
(3) Connect the other lead to the other end of the
circuit being tested. Low or no resistance means good
continuity.
STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND
(1) Remove the fuse and disconnect all items
involved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.
(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch
the voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that gen-
eral area of the wiring harness.
Fig. 7 TESTING FOR VOLTAGE POTENTIAL
Fig. 8 TESTING FOR CONTINUITY
1 - FUSE REMOVED FROM CIRCUIT
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 9
WIRING DIAGRAM INFORMATION (Continued)

STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND ON FUSES POWERING
SEVERAL LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the suspected fused circuits.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.
(4) Start connecting or energizing the items in the
fuse circuit one at a time. When the fuse blows the
circuit with the short to ground has been isolated.
STANDARD PROCEDURE - TESTING FOR A
VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to
the side of the circuit closest to the battery (Fig. 9).
(2) Connect the other lead of the voltmeter to the
other side of the switch, component or circuit.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.
SPECIAL TOOLS
WIRING/TERMINAL
Fig. 9 TESTING FOR VOLTAGE DROP
PROBING TOOL PACKAGE 6807
TERMINAL PICK TOOL SET 6680
TERMINAL REMOVING TOOLS 6932 AND 8638
TERMINAL REMOVING TOOL 6934
8W - 01 - 10 8W-01 WIRING DIAGRAM INFORMATIONWJ
WIRING DIAGRAM INFORMATION (Continued)

the same time, the power distribution system was
designed to provide ready access to these electrical
distribution points for the vehicle technician to use
when conducting diagnosis and repair of faulty cir-
cuits. The power distribution system can also prove
useful for the sourcing of additional electrical circuits
that may be required to provide the electrical current
needed to operate accessories that the vehicle owner
may choose to have installed in the aftermarket.
NOTE: DO NOT ATTEMPT TO SWAP POWER DIS-
TRIBUTION CENTERS FROM ONE VEHICLE TO
ANOTHER. MOST OF THESE ASSEMBLIES ARE
VEHICLE FEATURE SPECIFIC AND THEREFORE
NOT INTERCHANGEABLE. ALWAYS USE THE COR-
RECT PART NUMBERED ASSEMBLY WHEN DIAG-
NOSING OR REPLACING A POWER DISTRIBUTION
CENTER.
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
CIGAR LIGHTER OUTLET
DESCRIPTION
A cigar lighter outlet is standard equipment on
this model. On models equipped with the optional
Smoker's Package, the cigar lighter knob and heating
element are included. On models without the Smok-
er's Package, the cigar lighter outlet is equipped with
a snap fit plastic cap and is treated as an extra
accessory power outlet. The cigar lighter outlet is
installed in the instrument panel center lower bezel,
which is located near the bottom of the instrument
panel center stack area, below the heater and air
conditioner controls. The cigar lighter outlet is
secured by a snap fit within the center lower bezel.The cigar lighter outlet, plastic cap and the knob
and heating element unit are available for service
replacement. These components cannot be repaired
and, if faulty or damaged, they must be replaced.
OPERATION
The cigar lighter consists of two major components:
a knob and heating element unit, and the cigar
lighter base or outlet shell. The receptacle shell is
connected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The cigar lighter receives battery voltage from a fuse
in the junction block when the ignition switch is in
the Accessory or On positions.
The cigar lighter knob and heating element are
encased within a spring-loaded housing, which also
features a sliding protective heat shield. When the
knob and heating element are inserted in the outlet
shell, the heating element resistor coil is grounded
through its housing to the outlet shell. If the cigar
lighter knob is pushed inward, the heat shield slides
up toward the knob exposing the heating element,
and the heating element extends from the housing
toward the insulated contact in the bottom of the
outlet shell.
Two small spring-clip retainers are located on
either side of the insulated contact inside the bottom
of the outlet shell. These clips engage and hold the
heating element against the insulated contact long
enough for the resistor coil to heat up. When the
heating element is engaged with the contact, battery
current can flow through the resistor coil to ground,
causing the resistor coil to heat.
When the resistor coil becomes sufficiently heated,
excess heat radiates from the heating element caus-
ing the spring-clips to expand. Once the spring-clips
expand far enough to release the heating element,
the spring-loaded housing forces the knob and heat-
ing element to pop back outward to their relaxed
position. When the cigar lighter knob and element
are pulled out of the outlet shell, the protective heat
shield slides downward on the housing so that the
heating element is recessed and shielded around its
circumference for safety.
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET
For complete circuit diagrams, refer toHorn/Ci-
gar Lighter/Power Outletin Wiring Diagrams.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fused B(+) fuse in
Terminal Pick Kit 6680
8W - 97 - 2 8W-97 POWER DISTRIBUTIONWJ
POWER DISTRIBUTION (Continued)

The cigar lighter relay cannot be repaired or
adjusted and, if faulty or damaged, it must be
replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one mov-
able) electrical contacts. The movable (common feed)
relay contact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor or diode is con-
nected in parallel with the electromagnetic coil in the
relay, and helps to dissipate voltage spikes that are
produced when the coil is de-energized.
DIAGNOSIS AND TESTING - POWER OUTLET
RELAY
The power outlet / cigar lighter relay (Fig. 16) is
located in the junction block, below the driver side
end of the instrument panel in the passenger com-
partment. For complete circuit diagrams, refer to
Horn/Cigar Lighter/Power Outletin Wiring Dia-
grams.
WARNING: REFER TO RESTRAINTS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Remove the power outlet / cigar lighter relay
from the junction block. Refer to the procedure in
this group.
(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   5 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, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
DIAGNOSIS AND TESTING - RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) of
the junction block is connected to battery voltage and
should be hot at all times. Check for battery voltage
at the fused B(+) circuit cavity in the junction block
receptacle for the cigar lighter relay. If OK, go to
Step 2. If not OK, repair the fused B(+) circuit to the
Power Distribution Center (PDC) fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the fused B(+) fuse in the junction block that feeds
the cigar lighter when the relay is energized by the
ignition switch. There should be continuity between
the junction block cavity for relay terminal 87 and
the fused B(+) fuse in the junction block at all times.
If OK, go to Step 4. If not OK, repair the open fused
B(+) circuit to the junction block fuse as required.
(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. It receives battery
feed to energize the cigar lighter relay when the igni-
tion switch is in the Accessory or On positions. Turn
the ignition switch to the On position. Check for bat-
tery voltage at the fused ignition switch output (acc/
run) circuit cavity for relay terminal 85 in the
junction block receptacle for the cigar lighter relay. If
OK, go to Step 5. If not OK, repair the open fused
ignition switch output (acc/run) circuit to the ignition
switch as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. The junction block
cavity for this terminal should have continuity to
Fig. 16 Accessory Relay
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
8W - 97 - 14 8W-97 POWER DISTRIBUTIONWJ
POWER OUTLET RELAY (Continued)

SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Steering Column
Steering Wheel Nut61 45 Ð
Steering Column
Column Bracket Nuts12 Ð 105
Steering Column
Shaft Coupler Bolts49 36 Ð
SPECIAL TOOLS
STEERING COLUMN
IGNITION SWITCH
DESCRIPTION
The electrical ignition switch is located on the
steering column. It is used as the main on/off switch-
ing device for most electrical components. The
mechanical key lock cylinder is used to engage/disen-
gage the electrical ignition switch.
DIAGNOSIS AND TESTING - IGNITION SWITCH
ELECTRICAL DIAGNOSIS
For ignition switch electrical schematics, refer to
Ignition Switch in Wiring Diagrams.
MECHANICAL DIAGNOSIS (KEY DIFFICULT TO
ROTATE)
Vehicles equipped with an automatic trans-
mission and a floor mounted shifter:a cable is
used to connect the interlock device in the steering
column assembly, to the transmission floor shift
lever. This interlock device is used to lock the trans-
mission shifter in the PARK position when the key
lock cylinder is rotated to the LOCKED or ACCES-
SORY position. The interlock device within the steer-
ing column is not serviceable. If repair is necessary,the steering column assembly must be replaced,(Re-
fer to 19 - STEERING/COLUMN - REMOVAL).
If the ignition key is difficult to rotate to or from
the LOCK or ACCESSORY position, it may not be
the fault of the key cylinder or the steering column
components. The brake transmission shift interlock
cable may be out of adjustment,(Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
44RE/SHIFT INTERLOCK MECHANISM - ADJUST-
MENTS) .
Vehicles equipped with an automatic trans-
mission and a steering column mounted shifter:
an interlock device is located within the steering col-
umn. This interlock device is used to lock the trans-
mission shifter in the PARK position when the key
lock cylinder is in the LOCKED or ACCESSORY
position. If it is difficult to rotate the key to or from
the LOCK or ACCESSORY position, the interlock
device within the steering column may be defective.
This device is not serviceable. If repair is necessary,
the steering column assembly must be replaced,(Re-
fer to 19 - STEERING/COLUMN - REMOVAL).
Vehicles equipped with a manual transmis-
sion and a floor mounted shifter:on certain mod-
els, a lever is located on the steering column behind
the ignition key lock cylinder. The lever must be
manually operated to allow rotation of the ignition
key lock cylinder to the LOCK or ACCESSORY posi-
tion. If it is difficult to rotate the key to the LOCK or
ACCESSORY position, the lever mechanism may be
defective. This mechanism is not serviceable. If
repair is necessary, the steering column assembly
must be replaced,(Refer to 19 - STEERING/COL-
UMN - REMOVAL).
On other models, the ignition key cylinder must be
depressed to allow it to be rotated into the LOCK or
ACCESSORY position. If it is difficult to rotate the
key to the LOCK or ACCESSORY position, the lock
mechanism within the steering column may be defec-
tive. This mechanism is not serviceable. If repair is
Puller C-3894-A
19 - 12 COLUMNWJ
COLUMN (Continued)

KEY-IN IGNITION SWITCH
DESCRIPTION
The key-in ignition switch is concealed within and
integral to the ignition switch, which is mounted on
the steering column. The key-in ignition switch is
actuated by the ignition lock cylinder mechanism,
and is hard wired between a body ground and the
Body Control Module (BCM) through the instrument
panel wire harness.
The key-in ignition switch cannot be adjusted or
repaired and, if faulty or damaged, the entire igni-
tion switch unit must be replaced,(Refer to 19 -
STEERING/COLUMN/LOCK CYLINDER HOUSING
- REMOVAL). For complete circuit diagrams, refer to
Body Control Modulein the Contents of Wiring
Diagrams.
OPERATION
The key-in ignition switch closes a path to ground
for the BCM when the ignition key is inserted in the
ignition lock cylinder, and opens the ground path
when the key is removed from the ignition lock cyl-
inder. The BCM monitors the key-in ignition switch
status through an internal pull-up, then sends the
proper switch status messages to other electronic
modules over the Programmable Communications
Interface (PCI) data bus network. The key-in ignition
switch status is also used by the BCM as an input
for chime warning system operation.
DIAGNOSIS AND TESTING
KEY-IN IGNITION SWITCH
For complete circuit diagrams, refer toBody Con-
trol Modulein the Contents of Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. 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. Disconnect the instrument panel wire harness
connector from the key-in ignition switch connector
receptacle on the ignition switch. Check for continu-
ity between the key-in ignition switch sense and
ground terminals of the key-in ignition switch con-
nector receptacle. There should be continuity with
the key inserted in the ignition lock cylinder, and no
continuity with the key removed from the ignition
lock cylinder. If OK, go to Step 2. If not OK, replace
the faulty ignition switch unit.
(2) Check for continuity between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector for the key-in ignition switch and a good
ground. There should be continuity. If OK, go to Step
3. If not OK, repair the open ground circuit to ground
as required.
(3) Disconnect the gray 26-way instrument panel
wire harness connector from the Body Control Mod-
ule (BCM) connector receptacle. Check for continuity
between the key-in ignition switch sense circuit cav-
ity of the instrument panel wire harness connector
for the key-in ignition switch and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted key-in ignition switch
sense circuit as required.
(4) Check for continuity between the key-in igni-
tion switch sense circuit cavities of the instrument
panel wire harness connector for the key-in ignition
switch and the gray 26-way instrument panel wire
harness connector for the BCM. There should be con-
tinuity. If OK, use a DRB scan tool and the proper
Diagnostic Procedures manual to test the BCM. If
not OK, repair the open key-in ignition switch sense
circuit as required.
LOCK CYLINDER
REMOVAL
The ignition key must be in the key cylinder for
cylinder removal. The key cylinder must be removed
first before removing ignition switch.
(1) Disconnect negative battery cable at battery.
(2) If equipped with an automatic transmission,
place shifter in PARK position.
(3) Rotate key to ON position.
19 - 14 COLUMNWJ

SUNROOF
TABLE OF CONTENTS
page page
SUNROOF
DESCRIPTION.........................96
DIAGNOSIS AND TESTING - SUNROOF......96
DRAIN TUBE
REMOVAL............................100
INSTALLATION........................100
CONTROL MODULE
REMOVAL............................101
INSTALLATION........................101
DRIVE MOTOR
REMOVAL............................101
INSTALLATION........................101
WIND DEFLECTOR
REMOVAL............................102INSTALLATION........................102
GLASS PANEL
REMOVAL............................102
INSTALLATION........................103
ADJUSTMENTS
ADJUSTMENTS - FIT.................103
ADJUSTMENT - TIMING...............103
SUNSHADE
REMOVAL............................103
INSTALLATION........................103
HOUSING ASSEMBLY
REMOVAL............................104
INSTALLATION........................104
SUNROOF
DESCRIPTION
WARNING: Keep fingers and other body parts out
of sunroof opening at all times.
The sunroof features a power sliding glass panel
and a sunshade which can be manually positioned
anywhere along its travel, rearward of glass panel
front edge.
The sunroof is electrically operated from a switch
located on the mini overhead console. To operate the
sunroof the ignition switch must be in the On/Run
position. The sunroof has both manual and Express
Open modes of operation when opening. To open the
sunroof in the Express Open mode, the switch is
pressed rearward for less than1 second.This causes
the sunroof glass to automatically retract and stop at
a position slightly forward of full open that reduces
low speed wind buffeting. The sunroof can also be
opened manually by pressing and holding the switch
rearward. Once the switch is held reward for more
than1 second,the glass will retract in the manual
mode. Releasing the switch at any time during travel
will cause the sunroof to stop at the current position.
To close the sunroof from an open position, the
switch must be pushed forward and held until the
sunroof glass comes to a complete stop. Releasing the
switch at any time in this mode will cause the sun-
roof to stop at the current position.
To vent the sunroof from the closed position, the
switch is pushed forward and held. Releasing theswitch at any time during travel will cause the sun-
roof to stop at the current vent position. To reach the
fully vented position, continue to hold the switch for-
ward until vent motion stops. To close the sunroof
from the vent position, push and hold the switch
rearward until the glass comes to a complete stop.
DIAGNOSIS AND TESTING - SUNROOF
CAUTION: The sunroof motor is only to be powered
through the vehicle battery and vehicle wire har-
ness. Applying power to the sunroof motor leads
will cause failure of the sunroof control unit.
Before beginning sunroof diagnostics verify that all
other power accessories are in proper operating con-
dition. Refer to Sunroof Diagnostic Chart for possible
causes. If not, a common electrical problem may
exist. Refer to Group 8W, Wiring Diagrams, of this
publication for circuit, splice and component descrip-
tions. Check the condition of the circuit protection
(20 amp high current fuse (battery feed) located in
the Power Distribution Center (PDC). Check the
cover of the PDC for location of the fuse. Check for
correct operation of the sunroof delay relay. Inspect
all wiring connector pins for proper engagement and
continuity. Check for battery voltage at battery and
ignition pins of the power sunroof express module
wiring connector. Refer to Group 8W, Wiring Dia-
grams, for circuit information. The controller will not
operate at less than 10 volts. Check the ground at
the sunroof express module.
Before beginning diagnosis for wind noise or water
leaks, verify that the problem was not caused by
23 - 96 SUNROOFWJ

gap should be between 0.35 to 0.65 millimeter (0.014
to 0.026 inch). If the proper air gap is not obtained,
add or subtract shims as needed until the desired air
gap is obtained.
(9) Install the compressor shaft bolt. Tighten the
bolt to 13 N´m (115 in. lbs.).
NOTE: The shims may compress after tightening
the shaft bolt. Check the air gap in four or more
places to verify the air gap is still correct. Spin the
pulley before performing a final check of the air
gap.
(10) To complete the installation, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION)
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The compressor clutch relay is a International
Standards Organization (ISO) micro-relay. The termi-
nal designations and functions are the same as a con-
ventional ISO relay. However, the micro-relay
terminal orientation (footprint) is different, the cur-
rent capacity is lower, and the relay case dimensions
are smaller than those of the conventional ISO relay.
OPERATION
The compressor clutch relay is a electromechanical
device that switches battery current to the compres-
sor clutch coil when the Powertrain Control Module
(PCM) grounds the coil side of the relay. The PCM
responds to inputs from the a/c compressor switch on
the a/c heater control panel, the Automatic Zone Con-
trol (AZC) control module (if the vehicle is so
equipped), the a/c fin probe, and the a/c high pres-
sure transducer. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH RELAY - DIAGNOSIS AND TESTING)
The compressor clutch relay is located in the Power
Distribution Center (PDC) in the engine compart-
ment. Refer to the PDC label for relay identification
and location.
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH RELAY
For circuit descriptions and diagrams, refer to the
appropriate wiring information.
The compressor clutch relay (Fig. 10) is located in
the Power Distribution Center (PDC). Refer to the
PDC label for relay identification and location.Remove the relay from the PDC to perform the fol-
lowing tests:
(1) 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 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) 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, see the Relay Circuit Test procedure
in this group. If not OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, refer to the
appropriate wiring information..
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)
circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
Fig. 10 A/C COMPRESSOR CLUTCH RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 16 CONTROLSWJ
A/C COMPRESSOR CLUTCH (Continued)

(3) Check for continuity between each of the
blower motor switch input terminals of the resistor
and the resistor output terminal. In each case there
should be continuity. If OK, repair the wire harness
circuits between the blower motor switch and the
blower motor resistor or blower motor as required. If
not OK, replace the faulty blower motor resistor.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Depress locking tab and unplug the wire har-
ness connector from the blower motor resistor.
(3) Depress locking tab and unplug the resistor
connector from the blower motor.
(4) Remove the 2 screws that secure the blower
motor resistor to the HVAC housing.
(5) Remove the blower motor resistor from the
HVAC housing (Fig. 16).
INSTALLATION
(1) Install the blower motor resistor in the HVAC
housing. The housing is indexed to allow mounting in
only one position. Tighten the mounting screws to 2.2
N´m (20 in. lbs.).
(2) Plug in the wire harness connector to the
blower motor resistor.(3) Plug in the connector from the blower motor
resistor to the blower motor.
(4) Connect the battery negative cable.
BLOWER MOTOR SWITCH
DESCRIPTION
The A/C Heater blower motor is controlled by a
rotary-type blower motor switch, mounted in the A/C
Heater control panel. On vehicles with manual tem-
perature control systems, the switch allows the selec-
tion of four blower motor speeds, but will only
operate with the ignition switch in the On position
and the A/C Heater mode control switch in any posi-
tion, except Off. On vehicles with the Automatic Zone
Control (AZC) systems, the switch allows the selec-
tion of Lo Auto, Hi Auto, and ten speed settings
between Lo and Hi.
OPERATION
On manual temperature control systems, the
blower motor switch is connected in series with the
blower motor ground path through the a/c heater
mode control switch. The blower motor switch directs
this ground path to the blower motor through the
blower motor resistor wires, or directly to the blower
motor, as required to achieve the selected blower
motor speed.
On AZC systems, the blower motor switch is just
one of many inputs to the AZC control module. In the
manual blower modes, the AZC control module
adjusts the blower motor speed through the blower
motor controller as required to achieve the selected
blower switch position. In the auto blower modes, the
AZC control assembly is programmed to select and
adjust the blower motor speed through the blower
motor controller as required to achieve and maintain
the selected comfort level.
The blower motor switch cannot be repaired and, if
faulty or damaged, it must be replaced. The switch is
serviced only as a part of the a/c heater control
assembly.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH-MANUAL TEMPERATURE CONTROL
SYSTEM
For circuit descriptions and diagrams, refer to the
appropriate wiring information.
Fig. 16 BLOWER MOTOR RESISTOR REMOVE/
INSTALL
1 - BLOWER MOTOR RESISTOR
2 - BLOWER MOTOR
3 - GROUND STRAP
4 - ELECTRICAL CONNECTORS
5 - HEATER CORE TUBES
24 - 28 CONTROLSWJ
BLOWER MOTOR RESISTOR BLOCK (Continued)