ECU CHRYSLER CARAVAN 2003 Service Manual
Page 2027 of 2177
(7) Using hand pressure, press the top edge of the
rear heater-A/C control bezel upward until the two
snap clips are fully seated in their receptacles.
(8) Reconnect the battery negative cable.
(9) Using the DRB-IIItreset the Rear Tempera-
ture Selector calibration values.
(10) Verify that the Actuator Calibration of the
Front Control has passed. If an Actuator Calibration
has not passed correct any errors before proceeding
further.
(11) Rotate the Rear Temperature Selector counter
clockwise to the Cold Position, allow the Selector to
remain in the Cold Position for 5 seconds.
(12) Rotate the Rear Temperature Selector Clock-
wise to the Hot Position, allow the Selector to remain
in the Cold Position for 5 seconds.
(13) calibration is now complete.
BLEND DOOR ACTUATOR
DESCRIPTION
The blend door actuator is a reversible, 12-volt
Direct Current (DC), servo motor (Fig. 3). The single
blend door actuator is located on the outboard side of
the rear heater-A/C unit housing, below the mode
door actuator. The blend door actuator is mechani-
cally connected to the blend air door. The blend door
actuator is interchangeable with the actuator for the
mode door. Each actuator is contained within an
identical black molded plastic housing with an inte-
gral wire connector receptacle. Two integral mount-
ing tabs allow the actuator to be secured with two
screws to the rear heater-A/C unit housing. Eachactuator also has an identical output shaft with
splines that connects it to the pivot or linkage of the
proper door. The blend door actuator does not require
mechanical indexing to the blend air door pivot, as it
is electronically calibrated by the front heater-A/C
control module. The blend door actuator cannot be
adjusted or repaired and, if damaged or faulty, it
must be replaced.OPERATION
The blend door actuator is connected to the front
heater-A/C control module through the vehicle elec-
trical system by a dedicated two-wire take out and
connector of the rear HVAC wire harness. The blend
door actuator can move the blend air door in two
directions. When the front heater-A/C control module
pulls the voltage on one side of the motor connection
high and the other connection low, the blend air door
will move in one direction. When the module reverses
the polarity of the voltage to the motor, the blend air
door moves in the opposite direction. When the mod-
Fig. 2 Heater-A/C Control Bezel
1 - BEZEL
2 - SNAP CLIP (2)
3 - HEATER-A/C CONTROL
4 - SCREW (3)
5 - LOCATOR TAB (2)
Fig. 3 Blend Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - CONNECTOR
24 - 30 CONTROLS - REARRS
A/C-HEATER CONTROL (Continued)
ProCarManuals.com
Page 2028 of 2177
ule makes the voltage to both connections high or
both connections low, the blend air door stops and
will not move. These same motor connections also
provide a feedback signal to the front heater-A/C con-
trol module. This feedback signal allows the module
to monitor the operation and relative positions of the
blend door actuator and the blend air door. The front
heater-A/C control module learns the blend air door
stop positions during the calibration procedure and
will store a Diagnostic Trouble Code (DTC) for any
problems it detects in the blend door actuator cir-
cuits. A DTC can be retrieved and the blend door
actuator can be diagnosed using a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.
(4) Remove the screw that secures the back of the
rear heater-A/C unit housing to the right D-pillar.
(5) Remove the screw that secures the front of the
rear heater-A/C unit housing to the right quarter
inner panel.
(6) Carefully pull the top of the rear heater-A/C
unit housing away from the right quarter inner panel
far enough to reach between the rear heater-A/C unit
housing and the quarter inner panel to access the
blend door actuator (Fig. 4).
(7) Remove the two screws that secure the blend
door actuator to the rear heater-A/C unit housing.
(8) Pull the blend door actuator away from the
rear heater-A/C unit housing far enough to disengage
the actuator output shaft from the blend air door
pivot.
(9) Raise the blend door actuator far enough to
access and disconnect the rear HVAC wire harness
connector for the actuator from the actuator connec-
tor receptacle.
(10) Remove the blend door actuator from between
the rear heater-A/C unit housing and the quarter
inner panel.
INSTALLATION
(1) Position the blend door actuator between the
rear heater-A/C unit housing and the quarter inner
panel.
(2) Reconnect the rear HVAC wire harness connec-
tor for the blend door actuator to the actuator con-
nector receptacle.(3) Position the blend door actuator onto the rear
heater-A/C unit housing. If necessary, rotate the
actuator slightly to align the splines on the actuator
output shaft with those in the blend air door pivot.
(4) Install and tighten the two screws that secure
the blend door actuator to the rear heater-A/C unit
housing. Tighten the screws to 2 N´m (18 in. lbs.).
(5) Push the top of the rear heater-A/C unit hous-
ing back into position against the right quarter inner
panel.
(6) Install and tighten the screw that secures the
front of the rear heater-A/C unit housing to the right
quarter inner panel. Tighten the screw to 11 N´m (97
in. lbs.).
(7) Install and tighten the screw that secures the
back of the rear heater-A/C unit housing to the right
D-pillar. Tighten the screw to 11 N´m (97 in. lbs.).
(8) Install and tighten the two screws that secure
the top of the quarter trim panel attaching bracket to
the quarter inner panel. Tighten the screws to 1.7
N´m (15 in. lbs.).
Fig. 4 Mode Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - CONNECTOR
RSCONTROLS - REAR24-31
BLEND DOOR ACTUATOR (Continued)
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Page 2031 of 2177
(IPM) cover for rear blower motor relay identification
and location.
(2) Position the rear blower motor relay to the
proper receptacle in the IPM.
(3) Align the rear blower motor relay terminals
with the terminal cavities in the IPM relay recepta-
cle.
(4) Push down firmly on the rear blower motor
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install and latch the cover onto the IPM.
(6) Reconnect the battery negative cable.
BLOWER MOTOR RESISTOR
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C control
(Fig. 8). Models equipped with the optional Auto-
matic Temperature Control (ATC) use a blower powermodule, instead of the blower motor resistor. The
blower motor resistor is installed in a mounting hole
on the back of the rear heater-A/C unit housing,
directly above the expansion valve. The resistor con-
sists of a molded plastic mounting plate with an inte-
gral connector receptacle. Concealed behind the
mounting plate within the rear heater-A/C unit hous-
ing is an electrical circuit board.. The resistor mount-
ing plate is secured with two screws to the rear
heater-A/C unit housing and is accessed for service
by removing the right quarter and D-pillar trim pan-
els.
The blower motor resistor cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The blower motor resistor is connected to the vehi-
cle electrical system through a dedicated take out
and connector of the rear HVAC wire harness. The
blower motor resistor has an electrical circuit board
which will reduce the current flow through the
blower motor to change the blower motor speed. The
blower motor switch in the manual heater-A/C con-
trol directs the ground path for the blower motor
through the correct resistor wire to obtain the
selected speed. With the blower motor switch in the
lowest speed position, the ground path for the motor
is applied through both resistor wires. Each higher
speed selected with the blower motor switch applies
the blower motor ground path through fewer of the
resistor wires, increasing the blower motor speed.
When the blower motor switch is in the highest
speed position, the blower motor resistor wires are
bypassed and the blower motor receives a direct path
to ground through the blower motor switch. The
blower motor resistor may be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR
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.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the rear HVAC wire harness con-
nector for the blower motor resistor from the resistor
connector receptacle.
(3) Check for continuity between each of the
blower motor switch input terminals of the blower
motor resistor and the resistor output terminal. In
each case there should be continuity. If OK, repair
Fig. 8 Blower Motor Resistor
1 - REAR HEATER-A/C UNIT HOUSING
2 - D-PILLAR
3 - BLOWER PIGTAIL WIRE
4 - CONNECTOR
5 - EXPANSION VALVE
6 - SCREW (2)
7 - BLOWER MOTOR RESISTOR
24 - 34 CONTROLS - REARRS
BLOWER MOTOR RELAY (Continued)
ProCarManuals.com
Page 2032 of 2177
the wire harness circuits between the blower motor
switch and the blower motor resistor or the blower
motor pigtail wires as required. If not OK, replace
the faulty blower motor resistor.
REMOVAL
WARNING: THE BLOWER MOTOR RESISTOR MAY
GET VERY HOT DURING NORMAL OPERATION. IF
THE BLOWER MOTOR WAS TURNED ON, WAIT
FIVE MINUTES TO ALLOW THE BLOWER MOTOR
RESISTOR TO COOL BEFORE PERFORMING DIAG-
NOSIS OR SERVICE. FAILURE TO TAKE THIS PRE-
CAUTION CAN RESULT IN PERSONAL INJURY.
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
damage.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Disconnect the rear HVAC wire harness con-
nector for the blower motor resistor from the resistor
connector receptacle (Fig. 9).
(4) Remove the two screws that secure the blower
motor resistor to the rear heater-A/C unit housing.
(5) Remove the blower motor resistor from the rear
heater-A/C unit housing.
INSTALLATION
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
damage.
(1) Position the blower motor resistor into the rear
heater-A/C unit housing.
(2) Install and tighten the two screws that secure
the blower motor resistor to the rear heater-A/C unit
housing. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the rear HVAC wire harness connec-
tor for the blower motor resistor to the resistor con-
nector receptacle.
(4) Reinstall the right quarter trim panel and
right D-pillar trim panel onto the quarter inner
panel. (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - INSTALLATION).
(5) Reconnect the battery negative cable.INFRARED TEMPERATURE
SENSOR
DESCRIPTION
The rear infrared temperature sensor consists of
an infrared transducer that is concealed behind the
lens of the rear heater-A/C control in the headliner.
This sensor is used only on models equipped with the
optional Automatic Temperature Control (ATC) heat-
ing and air conditioning system. The rear infrared
temperature sensor is integral to the rear heater-A/C
control. The infrared sensor cannot be adjusted or
repaired and, if faulty or damaged, the rear heater-
A/C control unit must be replaced.
OPERATION
The rear infrared temperature sensor provides an
independent measurement input to the Automatic
Temperature Control (ATC) heater-A/C control mod-
ule that indicates the surface temperature of the rear
Fig. 9 Blower Motor Resistor
1 - REAR HEATER-A/C UNIT HOUSING
2 - D-PILLAR
3 - BLOWER PIGTAIL WIRE
4 - CONNECTOR
5 - EXPANSION VALVE
6 - SCREW (2)
7 - BLOWER MOTOR RESISTOR
RSCONTROLS - REAR24-35
BLOWER MOTOR RESISTOR (Continued)
ProCarManuals.com
Page 2033 of 2177
seat occupants. By using a surface temperature mea-
surement, rather than an air temperature measure-
ment, the ATC system is able to adjust itself to the
comfort level as perceived by the occupant. This
allows the system to detect and compensate for other
ambient conditions affecting comfort levels, such as
solar heat gain or evaporative heat loss. The ATC
system logic responds to the infrared sensor input by
calculating and adjusting the air flow temperature
and air flow rate needed to properly obtain and
maintain the selected comfort level temperatures for
the rear seat occupants. The ATC heater-A/C control
module continually monitors the infrared sensor cir-
cuit, and will store a Diagnostic Trouble Code (DTC)
for any problem it detects. This DTC information can
be retrieved and the infrared temperature sensor
diagnosed using a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
MODE DOOR ACTUATOR
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.
(4) Remove the screw that secures the back of the
rear heater-A/C unit housing to the right D-pillar.
(5) Remove the screw that secures the front of the
rear heater-A/C unit housing to the right quarter
inner panel.
(6) Carefully pull the top of the rear heater-A/C
unit housing away from the right quarter inner panel
far enough to reach between the rear heater-A/C unit
housing and the quarter inner panel to access the
mode door actuator (Fig. 10).
(7) Remove the two screws that secure the mode
door actuator to the rear heater-A/C unit housing.
(8) Pull the mode door actuator away from the
rear heater-A/C unit housing far enough to disengage
the actuator output shaft from the mode door link-
age.
(9) Raise the mode door actuator far enough to
access and disconnect the rear HVAC wire harness
connector for the actuator from the actuator connec-
tor receptacle.
(10) Remove the mode door actuator from between
the rear heater-A/C unit housing and the quarter
inner panel.
INSTALLATION
(1) Position the mode door actuator between the
rear heater-A/C unit housing and the quarter inner
panel.
(2) Reconnect the rear HVAC wire harness connec-
tor for the mode door actuator to the actuator connec-
tor receptacle.
(3) Position the mode door actuator onto the rear
heater-A/C unit housing. If necessary, rotate the
actuator slightly to align the splines on the actuator
output shaft with those in the mode door linkage.
(4) Install and tighten the two screws that secure
the mode door actuator to the rear heater-A/C unit
housing. Tighten the screws to 2 N´m (18 in. lbs.).
(5) Push the top of the rear heater-A/C unit hous-
ing back into position against the right quarter inner
panel.
(6) Install and tighten the screw that secures the
front of the rear heater-A/C unit housing to the right
quarter inner panel. Tighten the screw to 11 N´m (97
in. lbs.).
Fig. 10 Blend Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - CONNECTOR
24 - 36 CONTROLS - REARRS
INFRARED TEMPERATURE SENSOR (Continued)
ProCarManuals.com
Page 2034 of 2177
(7) Install and tighten the screw that secures the
back of the rear heater-A/C unit housing to the right
D-pillar. Tighten the screw to 11 N´m (97 in. lbs.).
(8) Install and tighten the two screws that secure
the top of the quarter trim panel attaching bracket to
the quarter inner panel. Tighten the screws to 1.7
N´m (15 in. lbs.).
(9) Reinstall the right quarter trim panel and
right D-pillar trim panel onto the quarter inner
panel. (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - INSTALLATION).
(10) Reconnect the battery negative cable.
(11) Perform the heater-A/C control calibration
procedure. (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS - FRONT/A/C-HEATER CON-
TROL - STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION).
POWER MODULE
DESCRIPTION
A blower power module is used on this model when
it is equipped with the optional Automatic Tempera-
ture Control (ATC) (Fig. 11). Models equipped with
the standard manual heater-A/C control use a blower
motor resistor, instead of the blower power module.The blower power module is installed in a mounting
hole in the back of the rear heater-A/C unit housing,
directly above the expansion valve. The module con-
sists of a molded plastic mounting plate with two
integral connector receptacles. Concealed behind the
mounting plate within the evaporator housing is the
power module electronic circuitry and a large finned,
heat sink. The module mounting plate is secured
with two screws to the rear heater-A/C unit housing
and is accessed for service by removing the right
quarter and D-pillar trim panels.
The power module heat sink will get hot when in
use. Do not touch the heat sink if the blower motor
has been running. The blower power module cannot
be adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
The blower power module is connected to the vehi-
cle electrical system through a dedicated take out
and connector of the rear HVAC wire harness. A sec-
ond connector receptacle receives the pigtail wire
connector from the blower motor. The blower power
module allows the microprocessor-based Automatic
Temperature Control (ATC) heater-A/C control mod-
ule to calculate and provide infinitely variable blower
motor speeds based upon either manual blower
switch input or the ATC programming using a Pulse
Width Modulated (PWM) circuit strategy. The PWM
voltage is applied to a comparator circuit which com-
pares the PWM signal voltage to the blower motor
feedback voltage. The resulting output drives the
power module circuitry, which adjusts the voltage
output received from the blower motor relay to
change or maintain the desired blower speed. The
blower power module is diagnosed using a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel.
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Disconnect the rear HVAC wire harness con-
nector for the blower power module from the resistor
connector receptacle (Fig. 12).
(4) Disconnect the blower motor pigtail wire con-
nector from the blower power module connector
receptacle.
(5) Remove the two screws that secure the blower
power module to the rear heater-A/C unit housing.
(6) Remove the blower power module from the rear
heater-A/C unit housing.
Fig. 11 Power Module
1 - REAR HEATER-A/C UNIT HOUSING
2 - SCREW (2)
3 - D-PILLAR
4 - BLOWER PIGTAIL WIRE
5 - REAR HVAC WIRE HARNESS
6 - EXPANSION VALVE
7 - BLOWER POWER MODULE
RSCONTROLS - REAR24-37
MODE DOOR ACTUATOR (Continued)
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Page 2035 of 2177
INSTALLATION
(1) Position the blower power module into the rear
heater-A/C unit housing.
(2) Install and tighten the two screws that secure
the blower power module to the rear heater-A/C unit
housing. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the blower motor pigtail wire to the
blower power module connector receptacle.
(4) Reconnect the rear HVAC wire harness connec-
tor for the blower power module to the module con-
nector receptacle.
(5) Reinstall the right quarter trim panel and
right D-pillar trim panel onto the quarter inner
panel. (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - INSTALLATION).
(6) Reconnect the battery negative cable.
Fig. 12 Power Module
1 - REAR HEATER-A/C UNIT HOUSING
2 - SCREW (2)
3 - D-PILLAR
4 - BLOWER PIGTAIL WIRE
5 - REAR HVAC WIRE HARNESS
6 - EXPANSION VALVE
7 - BLOWER POWER MODULE
24 - 38 CONTROLS - REARRS
POWER MODULE (Continued)
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Page 2038 of 2177
and also houses the remote front infrared tempera-
ture sensors.
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.
(2) Remove the center bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Place the center bezel face down on a suitable
work surface. Be certain to take the proper precau-
tions to protect the face of the center bezel from cos-
metic damage.
(4) If the vehicle is equipped with the optional
ATC system, disconnect the ATC remote infrared
temperature sensor jumper harness from the sensor
connector receptacle located on the bottom of the cen-
ter outlet housing (Fig. 3).(5) Remove the three screws that secure the bot-
tom of the outlet housing to the center bezel.
(6) Roll the bottom of the outlet housing upwards
towards the top of the center bezel far enough to dis-
engage the retainer features on the top of the outlet
housing from their receptacles at the top of the cen-
ter bezel.
(7) Remove the center bezel outlets and housing
from the center bezel as a unit.
REMOVAL - DEMISTER OUTLET
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the outer perimeter of the
demister outlet away from the instrument panel top
pad until the snap features on the outlet are released
(Fig. 4).
(2) Remove the demister outlet from the demister
duct opening in the instrument panel top pad.
REMOVAL - FRONT DOOR REAR OUTLET
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the front door
inner panel. (Refer to 23 - BODY/DOOR - FRONT/
TRIM PANEL - REMOVAL).
(3) Using a trim stick or another suitable wide
flat-bladed tool, depress the four latch features (two
top and two bottom) that secure the outlet to the
inside of the trim panel rear outlet opening and push
the outlet unit out through the opening (Fig. 5).
(4) Remove the front door rear outlet through the
outside of the front door trim panel outlet opening.
Fig. 3 Center Bezel Outlets
1 - CENTER BEZEL
2 - CENTER BEZEL OUTLETS
3 - SCREW (3)
4 - INSTRUMENT PANEL SWITCH BANK
5 - CONNECTOR (ATC ONLY)
6 - JUMPER HARHESS (ATC ONLY)
Fig. 4 Demister Outlet
1 - DEMISTER OUTLET
2 - INSTRUMENT PANEL TOP PAD
3 - TRIM STICK
RSDISTRIBUTION - FRONT24-41
AIR OUTLETS (Continued)
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Page 2039 of 2177
REMOVAL - INSTRUMENT PANEL OUTLET
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the outer perimeter of the
instrument panel outlet away from the instrument
panel top pad until the snap features on the outlet
are released (Fig. 6).
(2) Remove the instrument panel outlet from the
panel duct opening in the instrument panel top pad.
INSTALLATION
INSTALLATION - CENTER BEZEL OUTLETS
(1) Position the center bezel outlets and housing
onto the center bezel as a unit.
(2) Engage the retainer features on the top of the
outlet housing with their receptacles at the top of the
center bezel, then roll the bottom of the outlet hous-
ing downwards towards the center bezel.
(3) Install and tighten the three screws that secure
the bottom of the outlet housing to the center bezel.
Tighten the screws to 2 N´m (17 in. lbs.).
(4) If the vehicle is equipped with the optional
ATC system, reconnect the ATC remote infrared tem-
perature sensor jumper harness to the sensor connec-
tor receptacle located on the bottom of the center
outlet housing.
(5) Reinstall the center bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(6) Reconnect the battery negative cable.
INSTALLATION - DEMISTER OUTLET
(1) Position the demister outlet over the demister
duct opening in the instrument panel top pad.
(2) Using hand pressure, press the demister outlet
firmly and evenly into the instrument panel top pad
opening until the snap features on the outlet are
fully engaged.
INSTALLATION - FRONT DOOR REAR OUTLET
(1) Position the front door rear outlet through the
outside of the front door trim panel outlet opening.
(2) While keeping the outlet aligned with the door
duct opening behind the trim panel, use hand pres-
sure to press the outlet firmly and evenly through
the outside of the front door trim panel outlet open-
ing until the four latch features (two top and two bot-
tom) that secure the outlet to the inside of the
opening are fully engaged.
(3) Reinstall the trim panel onto the front door
inner panel. (Refer to 23 - BODY/DOOR - FRONT/
TRIM PANEL - INSTALLATION).
(4) Reconnect the battery negative cable.
INSTALLATION - INSTRUMENT PANEL OUTLET
(1) Position the instrument panel outlet into the
panel duct opening in the instrument panel top pad.
(2) Using hand pressure, press the instrument
panel outlet firmly and evenly into the instrument
panel top pad opening until the snap features on the
outlet are fully engaged.
Fig. 5 Front Door Rear Outlet
1 - FRONT DOOR REAR OUTLET
2 - FRONT DOOR TRIM PANEL
Fig. 6 Instrument Panel Outlet
1 - INSTRUMENT PANEL TOP PAD
2 - INSTRUMENT PANEL OUTLET
3 - TRIM STICK
24 - 42 DISTRIBUTION - FRONTRS
AIR OUTLETS (Continued)
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Page 2040 of 2177
BLOWER MOTOR
DESCRIPTION
The blower motor is a 12-volt, Direct Current (DC)
motor with a squirrel cage-type blower wheel that is
secured to the blower motor shaft (Fig. 7). The
blower motor and wheel are located near the passen-
ger side end of the heater-A/C unit within the two
halves of the intake air housing in the passenger
compartment below the instrument panel. The
blower motor and blower motor wheel are a factory
balanced unit and cannot be adjusted or repaired. If
faulty or damaged, the blower motor and blower
wheel must be replaced as a unit.
OPERATION
The blower motor will operate whenever the igni-
tion switch is in the On position and the heater-A/C
control power is turned on. The blower motor can
only be turned off by turning off the power at the
heater-A/C control. The blower motor receives battery
current whenever the front blower motor relay is
energized. The front blower motor relay output cir-
cuit is protected by a fuse in the Intelligent Power
Module (IPM) located in the engine compartment
near the battery. In the Manual system, the blower
motor speed is controlled by regulating the path to
ground through the blower control switch and the
blower motor resistor. In the ATC system, the blower
motor speed is controlled by an electronic blower
power module, which uses a pulse width modulated
input from the ATC module and feedback from the
blower motor to regulate the blower motor ground
path it provides. The blower motor and wheel areused to control the velocity of air moving through the
heater-A/C unit housing. The blower motor controls
the velocity of the air flowing through the heater-A/C
housing by spinning the blower wheel within the
housing at the selected speed or, in the ATC system,
at the selected or programmed speed.
DIAGNOSIS AND TESTING - BLOWER MOTOR
BLOWER MOTOR INOPERATIVE
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) Check the fuse (Fuse 10 - 40 ampere) in the
Intelligent Power Module (IPM). If OK, go to Step 2.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(2) Turn the ignition switch to the On position. Be
certain that the heater-A/C control power is turned
on. Check for battery voltage at the fuse (Fuse 10 -
40 ampere) in the IPM. If OK, go to Step 3. If not
OK, proceed to diagnosis of the front blower motor
relay. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/BLOWER MOTOR
RELAY - DIAGNOSIS AND TESTING).
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the front HVAC wire harness connector
for the front blower motor resistor (Manual Temper-
ature Control) or the front blower power module
(Automatic Temperature Control) from the resistor or
module connector receptacle. Reconnect the battery
negative cable. Turn the ignition switch to the On
position. Be certain that the heater-A/C control
power is turned on. Check for battery voltage at the
fused front blower motor relay output circuit cavity
of the front HVAC wire harness connector for the
front blower motor resistor (MTC) or the front blower
power module (ATC). If OK, go to Step 4. If not OK,
repair the open fused front blower motor relay output
circuit to the IPM as required.
Fig. 7 Blower Motor
1 - BLOWER MOTOR
2 - RUBBER GROMMET
3 - BLOWER MOTOR CONNECTOR
4 - MOUNTING TABS
RSDISTRIBUTION - FRONT24-43
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