COOLING/ACCESSORY DRIVE/DRIVE BELTS -
3.3L/3.8L - INSTALLATION).
(15) Lower the vehicle.
(16) Reconnect the battery negative cable.
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C-heater control to the A/C
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat
the opposing friction surfaces and provide a higher
compressor clutch torque capability.
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The compressor clutch relay (Fig. 7) is a Interna-
tional Standards Organization (ISO) micro-relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The ISO
micro-relay terminal functions are the same as a con-
ventional ISO relay. However, the ISO micro-relay
terminal pattern (or footprint) is different, the cur-
rent capacity is lower, and the physical dimensions
are smaller than those of the conventional ISO relay.
The A/C compressor clutch relay is located in the
Integrated Power Module (IPM) in the engine com-
partment. See the fuse and relay layout map molded
into the inner surface of the IPM cover for A/C com-
pressor clutch relay identification and location.The black, molded plastic case is the most visible
component of the A/C compressor clutch relay. Five
male spade-type terminals extend from the bottom of
the base to connect the relay to the vehicle electrical
system, and the ISO designation for each terminal is
molded into the base adjacent to each terminal. The
ISO terminal designations are as follows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
OPERATION
The A/C compressor clutch relay is an electrome-
chanical switch that uses a low current input from
the powertrain control module (PCM) to control the
high current output to the compressor clutch electro-
magnetic coil. The movable common feed contact
point is held against the fixed normally closed con-
tact 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 nor-
mally closed contact point, and holds it against the
fixed normally open contact point. When the relay
coil is de-energized, spring pressure returns the mov-
able contact point back against the fixed normally
closed contact point. The resistor or diode is con-
nected in parallel with the relay coil in the relay, and
helps to dissipate voltage spikes and electromagnetic
interference that can be generated as the electromag-
netic field of the relay coil collapses.
The compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the integrated power module (IPM). The
inputs and outputs of the A/C compressor clutch
relay include:
²The common feed terminal (30) receives a bat-
tery current input from a fuse in the IPM through a
fused B(+) circuit at all times.
²The coil ground terminal (85) receives a ground
input from the PCM through the compressor clutch
relay control circuit only when the PCM electroni-
cally pulls the control circuit to ground.
²The coil battery terminal (86) receives a battery
current input from the PCM through a fused ignition
switch output (run-start) circuit only when the igni-
tion switch is in the On or Start positions.
Fig. 7 A/C Compressor Clutch Relay
RSCONTROLS - FRONT24-19
A/C COMPRESSOR CLUTCH/COIL (Continued)
BLEND DOOR ACTUATOR
DESCRIPTION
The blend door actuators are reversible, 12-volt
Direct Current (DC), servo motors. Models with the
single zone heater and air conditioner system have a
single blend air door, which is controlled by a single
blend door actuator. Models with the optional dual
zone front heater and air conditioner system have
dual blend air doors, which are controlled by two
blend door actuators. The single zone blend door
actuator is located on the driver's side end of the
HVAC housing, close to the middle of the distribution
housing. In the dual zone system, the same blend
door actuator used for the single zone system
becomes the passenger blend door actuator, and is
mechanically connected to only the passenger side
blend air door. In the dual zone system, a second sep-
arate blend door actuator is also located on the
driver side end of the HVAC housing, close to the
middle of the distribution housing, and is mechani-
cally connected to only the driver's side blend air
door.
The blend door actuators are interchangeable with
each other, as well as with the actuators for the
mode door and the recirculation air door. Each actua-
tor is contained within an identical black molded
plastic housing with an integral wire connector
receptacle. Two integral mounting tabs allow the
actuator to be secured with two screws to the distri-
bution housing. Each actuator also has an identical
output shaft with splines that connects it to the link-
age that drives the proper blend air door. The blend
door actuators do not require mechanical indexing to
the blend door linkage, as they are electronically cal-
ibrated by the heater-A/C control module.
OPERATION
Each blend door actuator is connected to the A/C-
heater control through the vehicle electrical system
by a dedicated two-wire lead and connector from the
HVAC wire harness. The blend door actuator can
move the blend-air door in two directions. When the
A/C-heater control 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 A/C-heater control reverses the polarity of
the voltage to the motor, the blend-air door moves in
the opposite direction. When the A/C-heater control
makes the voltage to both connections high or both
connections low, the blend-air door stops and will not
move. The motor connections also provide a feedback
signal to the A/C-heater control. This feedback signal
allows the A/C-heater control to monitor the opera-
tion and relative positions of the blend door actuator
and the blend-air door. The A/C-heater control learnsthe blend 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 circuits.
The blend door actuator can be diagnosed using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures for more information. The blend door actuators
cannot be adjusted or repaired and, if damaged or
faulty, they must be replaced.
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.
NOTE: The single zone heating and air conditioning
system is equipped with a single blend door actua-
tor. The dual zone system has two blend door
actuators, one for the driver side blend air door and
one for the passenger side blend air door. The
same service procedures can be used for each of
these actuators.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the silencer from beneath the driver
side end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL SILENCER - REMOVAL).
(3) Disconnect the wire harness connector from the
blend door actuator(s) (Fig. 11).
(4) Remove the two screws that secure the blend
door actuator to the distribution housing.
(5) Remove the blend door actuator.
INSTALLATION
(1) Position the blend door actuator onto the distri-
bution housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the blend air door linkage.
(2) Install the two screws that secure the blend
door actuator to the housing. Tighten the screws to 2
N´m (17 in. lbs.).
RSCONTROLS - FRONT24-23
(3) Connect the HVAC wire harness connector to
the blend door actuator.
(4) Install the silencer under the driver side end of
the instrument panel (Refer to 23 - BODY/INSTRU-
MENT PANEL/INSTRUMENT PANEL SILENCER -
INSTALLATION).
(5) Reconnect the battery negative cable.
(6) Perform the heater-A/C control calibration pro-
cedure (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/A/C-HEATER CONTROL
- STANDARD PROCEDURE - HEATER-A/C CON-
TROL CALIBRATION).
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is a International Stan-
dards Organization (ISO) mini-relay (Fig. 12). Relays
conforming to the ISO specifications have common
physical dimensions, current capacities, terminal pat-
terns, and terminal functions. The ISO mini-relay
terminal functions are the same as a conventional
ISO relay. However, the ISO mini-relay terminal pat-
tern (or footprint) is different, the current capacity is
lower, and the physical dimensions are smaller than
those of the conventional ISO relay. The blower
motor relay is located in the Integrated Power Mod-
ule (IPM), which is in the engine compartment near
the battery. See the fuse and relay layout map
molded into the inner surface of the IPM cover for
blower motor relay identification and location.The black, molded plastic case is the most visible
component of the blower motor relay. Five male
spade-type terminals extend from the bottom of the
base to connect the relay to the vehicle electrical sys-
tem, and the ISO designation for each terminal is
molded into the base adjacent to each terminal. The
ISO terminal designations are as follows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
The blower motor relay cannot be adjusted or
repaired. If the relay is damaged or faulty, it must be
replaced.
OPERATION
The blower motor relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control the high current
output to the blower motor resistor (manual heater-
A/C control) or blower power module (ATC control).
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 wind-
ings. This electromagnetic field draws the movable
relay contact point away from the fixed normally
closed contact point, and holds it against the fixed
Fig. 11 Blend Door Actuator - LHD Shown, RHD
Typical
1 - WIRE HARNESS CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)Fig. 12 Blower Motor Relay
24 - 24 CONTROLS - FRONTRS
BLEND DOOR ACTUATOR (Continued)
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C system.
Models equipped with the optional Automatic Tem-
perature Control (ATC) system use a blower power
module, instead of the blower motor resistor block
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS/POWER MODULE - DESCRIPTION).
The blower motor resistor block is mounted to the
rear of the HVAC housing, directly behind the glove
box opening in the instrument panel. The resistor
block consists of a molded plastic mounting plate
with two integral connector receptacles. Concealed
behind the mounting plate are four coiled resistor
wires contained within a protective stamped steel
cage. The blower motor resistor block is accessed for
service by removing the glove box from the instru-
ment panel.
OPERATION
The blower motor resistor block is connected to the
vehicle electrical system through a dedicated take
out and connector of the instrument panel wire har-
ness. A second connector receptacle receives the pig-
tail wire connector from the blower motor. The
blower motor resistor has multiple resistor wires,
each of 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
system 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 all of the resistor wires. Each higher speed
selected with the blower motor switch applies the
blower motor ground path through fewer of the resis-
tor wires, increasing the blower motor speed.
The blower motor resistor cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR BLOCK
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.
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor resistor block.
(4) 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, blower motor or blower motor
relay as required. If not OK, replace the faulty
blower motor resistor block.
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.
WARNING: THE BLOWER MOTOR RESISTOR
BLOCK MAY GET VERY HOT DURING NORMAL
OPERATION. IF THE BLOWER MOTOR WAS
TURNED ON PRIOR TO SERVICING THE BLOWER
MOTOR RESISTOR BLOCK, WAIT FIVE MINUTES
TO ALLOW THE BLOWER MOTOR RESISTORS TO
COOL BEFORE PERFORMING DIAGNOSIS OR SER-
VICE. FAILURE TO TAKE THIS PRECAUTION CAN
RESULT IN PERSONAL INJURY.
24 - 26 CONTROLS - FRONTRS
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 glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor resistor block (Fig. 14).
(4) Remove the two screws that secure the blower
motor resistor block to the HVAC housing.
(5) Remove the resistor block from the HVAC
housing.
INSTALLATION
(1) Position the blower motor resistor block into
the HVAC housing.
(2) Install the two screws that secure the blower
motor resistor block to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the two wire connectors to the resistor
block.
(4) Install the glove box (Refer to 23 - BODY/IN-
STRUMENT PANEL/GLOVE BOX - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
NOTE: The following applies to RS models only. RG
models use an expansion valve mounted evapora-
tor temperature sensor for both manual and auto-
matic temperature control systems due to A/C-
heater control calibration requirements.
The evaporator temperature sensor used for the
manual temperature control (MTC) system is
installed on the top of the HVAC housing behind the
instrument panel and measures the air temperature
downstream of the evaporator (Fig. 15). The sensor is
an electrical thermistor in a plastic housing that is
inserted into the HVAC housing. Two terminals
within the molded plastic connector receptacle on the
sensor connect it to the vehicle electrical system
through a take out and connector of the HVAC wire
harness.
The evaporator temperature sensor used for the
automatic temperature control (ATC) system is
installed on the top of the expansion valve in the
right rear corner of the engine compartment and
measures the temperature of the evaporator coils
(Fig. 16). The sensor has a small probe that is
Fig. 14 Blower Motor Resistor Block - Typical
1 - BLOWER MOTOR RESISTOR
2 - INSTRUMENT PANEL WIRE HARNESS
3 - SCREW (2)
4 - GLOVE BOX OPENING REINFORCEMENT
5 - BLOWER MOTOR PIGTAIL WIRE HARNESS
6 - HVAC HOUSING
Fig. 15 Evaporator Temperature Sensor - MTC
System
1 - EVAPORATOR TEMPERATURE SENSOR
2 - HVAC HOUSING
3 - A/C EVAPORATOR
RSCONTROLS - FRONT24-27
BLOWER MOTOR RESISTOR BLOCK (Continued)
(5) Remove the mode door actuator from the distri-
bution housing.
INSTALLATION
(1) Position the mode door actuator onto the HVAC
distribution housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the mode door linkage.
(2) Install the two screws that secure the mode
door actuator to the distribution housing. Tighten the
screws to 2 N´m (17 in. lbs.).
(3) Connect the wire harness connector to the
mode door actuator.
(4) Install the silencer under the driver side end of
the instrument panel (Refer to 23 - BODY/INSTRU-
MENT PANEL/INSTRUMENT PANEL SILENCER -
INSTALLATION).
(5) Reconnect the negative battery cable.
(6) Perform the A/C-heater control calibration pro-
cedure (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/A/C-HEATER CONTROL
- STANDARD PROCEDURE - HEATER-A/C CON-
TROL CALIBRATION).
POWER MODULE - BLOWER
MOTOR
DESCRIPTION
A blower motor power module is used on this
model when it is equipped with the optional Auto-
matic Temperature Control (ATC) system. Modelsequipped with the standard manual heater-A/C sys-
tem use a blower motor resistor block, instead of the
blower motor power module (Refer to 24 - HEATING
& AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - DESCRIPTION).
The blower motor power module is mounted to the
rear of the HVAC housing, directly behind the glove
box opening in the instrument panel. The module
consists of a molded plastic mounting plate with two
integral connector receptacles. Concealed behind the
mounting plate is the power module electronic cir-
cuitry and a large finned, heat sink. The blower
motor power module is accessed for service by remov-
ing the glove box from the instrument panel.
OPERATION
The blower motor power module is connected to the
vehicle electrical system through a dedicated lead
and connector from the instrument panel wire har-
ness. A second connector receptacle receives a wire
lead connector from the blower motor. The blower
motor power module allows the microprocessor-based
Automatic Temperature Control (ATC) heater-A/C
control module to calculate and provide infinitely
variable blower motor speeds based upon either man-
ual blower switch input or the ATC programming
using a Pulse Width Modulated (PWM) circuit strat-
egy. The PWM voltage is applied to a comparator cir-
cuit which compares 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 motor power module is diagnosed using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures.
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.
Fig. 20 Mode Door Actuator - LHD Shown, RHD
Typical
1 - WIRE HARNESS CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)
RSCONTROLS - FRONT24-31
MODE DOOR ACTUATOR (Continued)
WARNING: THE HEAT SINK FOR THE BLOWER
MOTOR POWER MODULE MAY GET VERY HOT
DURING NORMAL OPERATION. IF THE BLOWER
MOTOR WAS TURNED ON PRIOR TO SERVICING
THE BLOWER MOTOR POWER MODULE, WAIT
FIVE MINUTES TO ALLOW THE HEAT SINK TO
COOL BEFORE PERFORMING DIAGNOSIS OR SER-
VICE. FAILURE TO TAKE THIS PRECAUTION CAN
RESULT IN PERSONAL INJURY.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the glove box from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(3) Disconnect the two wire harness connectors
from the blower motor power module (Fig. 21).
(4) Remove the two screws that secure the blower
motor power module to the HVAC housing.
(5) Remove the blower motor power module from
the HVAC housing.
INSTALLATION
(1) Position the blower motor power module into
the HVAC housing.
(2) Install the two screws that secure the blower
motor power module to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the two wire connectors to the blower
motor power module.
(4) Install the glove box (Refer to 23 - BODY/IN-
STRUMENT PANEL/GLOVE BOX - INSTALLA-
TION).
(5) Reconnect the negative battery cable.
RECIRCULATION DOOR
ACTUATOR
DESCRIPTION
The recirculation door actuator is a reversible,
12-volt direct current (DC), servo motor. The single
recirculation door actuator is located on the passen-
ger side end of the HVAC housing, on the air inlet
housing. The recirculation door actuator is mechani-
cally connected to the recirculation-air door. The
recirculation door actuator is interchangeable with
the actuators for the blend-air door(s) and the mode
door. Each actuator is contained within an identical
black molded plastic housing with an integral wire
connector receptacle. Two integral mounting tabs
allow the actuator to be secured with two screws to
the air inlet housing. Each actuator also has an iden-
tical output shaft with splines that connects it to the
linkage that drives the recirculation-air door. The
recirculation door actuator does not require mechan-
ical indexing to the recirculation-air door, as it is
electronically calibrated by the A/C-heater control.
OPERATION
The recirculation door actuator is connected to the
heater-A/C control module through the vehicle elec-
trical system by a dedicated two-wire lead and con-
nector of the HVAC wire harness. The recirculation
door actuator can move the recirculation door in two
directions. When the heater-A/C control module pulls
the voltage on one side of the motor connection high
and the other connection low, the recirculation air
door will move in one direction. When the module
reverses the polarity of the voltage to the motor, the
recirculation air door moves in the opposite direction.
When the module makes the voltage to both connec-
tions high or both connections low, the recirculation
air door stops and will not move. These same motor
connections also provide a feedback signal to the
heater-A/C control module. This feedback signal
allows the module to monitor the operation and rela-
tive position of the recirculation door actuator and
the recirculation air door. The heater-A/C control
module learns the recirculation air door stop posi-
tions during the calibration procedure and will store
a Diagnostic Trouble Code (DTC) for any problems it
detects in the recirculation door actuator circuits.
The recirculation door actuator can be diagnosed
using a DRBIIItscan tool. Refer to Body Diagnostic
Procedures for more information. The recirculation
door actuator cannot be adjusted or repaired and, if
damaged or faulty, it must be replaced.
Fig. 21 Blower Motor Power Module - Typical
1 - POWER MODULE
2 - LOWER GLOVE BOX OPENING REINFORCEMENT
3 - HVAC HOUSING
24 - 32 CONTROLS - FRONTRS
POWER MODULE - BLOWER MOTOR (Continued)
(6) If required, remove the three screws that
secure the rear A/C-heater control to the bezel and
remove the control from the bezel (Fig. 2).
INSTALLATION
(1) If removed, position the rear A/C-heater control
onto the bezel.
(2) If removed, install the three screws that secure
the rear A/C-heater control to the bezel. Tighten the
screws to 2 N´m (17 in. lbs.).
(3) Position the rear A/C-heater control near the
headliner.
(4) Connect the wire harness connector to the rear
A/C-heater control.
(5) Insert the locator tabs on the back of the rear
A/C-heater control bezel over the forward edge of the
headliner opening.
(6) Slide the rear A/C-heater control bezel forward
far enough to align the snap clips on the bezel with
the receptacles on the headliner.
(7) Using hand pressure, press the top edge of the
rear A/C-heater 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 rear blend door actuator is a reversible,
12-volt Direct Current (DC), servo motor. The single
blend door actuator is located on the outboard side of
the rear HVAC housing, below the mode door actua-
tor. The blend door actuator is mechanically con-
nected to the blend air door.
The rear 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 integral wire connector receptacle.
Two integral mounting tabs allow the actuator to be
secured with two screws to the rear HVAC housing.
Each actuator also has an identical output shaft with
splines that connects it to the pivot or linkage of the
proper door. The rear 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.
OPERATION
The rear blend door actuator is connected to the
front heater-A/C control module through the vehicle
electrical 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 direc-
tion. When the module 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 control module. This feedback signal
allows the module to monitor the operation and rela-
tive 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 circuits.
The rear blend door actuator can be diagnosed
using a DRBIIItscan tool. Refer to Body Diagnostic
Procedures for more information. The rear blend door
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)
RSCONTROLS - REAR24-35
A/C-HEATER CONTROL (Continued)