2002 CHRYSLER TOWN AND COUNTRY calibration

(5) Install and tighten the three screws that secure
the heater core shield to the left end of the heater/air
conditioner housing. Tighten the screws to 2 N´m (17
in. lbs.).
(6) Reinstall the silencer under the driver side end
of the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL
SILENCER - INSTALLATION).
(7) Reconnect the battery negative cable.
(8) 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 (Fig. 6) is a International
Standards Organization (ISO) mini-relay. Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminal
patterns, 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 Intelligent Power Mod-
ule (IPM), which is in the engine compartment near
the battery. See the fuse and relay layout mapmolded 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.
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
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. The resistor or diode is connected in
parallel with the relay coil in the relay, and helps to
dissipate voltage spikes and electromagnetic interfer-
ence that can be generated as the electromagnetic
field of the relay coil collapses.
The blower motor relay terminals are connected to
the vehicle electrical system through a receptacle in
the Intelligent Power Module (IPM). The inputs and
outputs of the blower motor relay include:
²The common feed terminal (30) receives a bat-
tery current input from the battery through a B(+)
circuit at all times.
²The coil ground terminal (85) receives a ground
input through the front/rear blower motor relay con-
trol circuit only when the FCM electronically pulls
the control circuit to ground.
²The coil battery terminal (86) receives a battery
current input from the battery through a B(+) circuit
at all times.
²The normally open terminal (87) provides a bat-
tery current output to the blower motor resistor
(manual heater-A/C control) or blower power module
(automatic heater-A/C control) through a fuse in the
IPM on the fused front blower motor relay output cir-
cuit only when the blower motor relay coil is ener-
gized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the blower motor
relay coil is de-energized.
Fig. 6 Blower Motor Relay
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
RSCONTROLS - FRONT24-13
BLEND DOOR ACTUATOR (Continued)
ProCarManuals.com

it to the linkage that drives the mode door. The mode
door actuator does not require mechanical indexing
to the mode door linkage, as it is electronically cali-
brated by the heater-A/C control module. The mode
door actuator cannot be adjusted or repaired and, if
damaged or faulty, it must be replaced.
OPERATION
The mode door actuator is connected to the heater-
A/C control module through the vehicle electrical sys-
tem by a dedicated two-wire take out and connector
of the HVAC wire harness. The mode door actuator
can move the mode 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 con-
nection low, the mode door will move in one direction.
When the module reverses the polarity of the voltage
to the motor, the mode door moves in the opposite
direction. When the module makes the voltage to
both connections high or both connections low, the
mode 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 mode door actuator and the mode
door. The heater-A/C control module learns the mode
door stop positions during the calibration procedure
and will store a Diagnostic Trouble Code (DTC) for
any problems it detects in the mode door actuator
circuits. The mode door actuator can be diagnosed
using a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(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 HVAC wire harness connector
for the mode door actuator from the actuator connec-
tor receptacle (Fig. 21).
(4) Remove the two screws that secure the mode
door actuator to the distribution housing.
(5) Remove the mode door actuator from the distri-
bution housing.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the mode door actuator onto the heat-
er/AC housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the mode door linkage.
Fig. 21 Mode Door Actuator
1 - CONNECTOR
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - DRIVER BLEND DOOR ACTUATOR (DUAL-ZONE ONLY)
5 - HEATER CORE
6 - BLEND DOOR ACTUATOR (SINGLE ZONE) OR PASSENGER
BLEND DOOR ACTUATOR (DUAL-ZONE)
RSCONTROLS - FRONT24-25
MODE DOOR ACTUATOR (Continued)
ProCarManuals.com

(2) Install and tighten the two screws that secure
the mode door actuator to the distribution housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector
for the mode door actuator to the actuator connector
receptacle.
(4) Reinstall the silencer under the driver side end
of the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT 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).
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. 22). 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 evaporator housing, directly behind the
glove box opening of the instrument panel. The mod-
ule consists 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 evaporator housingand is accessed for service by rolling down the glove
box from the instrument panel.
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 instrument panel wire harness.
A second connector receptacle receives the pigtail
wire connector from the blower motor. The blower
power module allows the microprocessor-based Auto-
matic Temperature Control (ATC) heater-A/C control
module 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 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 power module is diagnosed using a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Open the glove box.
(3) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box downward.
(4) Reach through the glove box opening to access
and disconnect the instrument panel wire harness
Fig. 22 Power Module
1 - POWER MODULE
2 - LOWER GLOVE BOX OPENING REINFORCEMENT
3 - EVAPORATOR HOUSING
24 - 26 CONTROLS - FRONTRS
MODE DOOR ACTUATOR (Continued)
ProCarManuals.com

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 the appropriate
diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Pull the carpet on the passenger side front
floor away from the dash panel far enough to access
the recirculation door actuator.
(3) Disconnect the HVAC wire harness connector
for the recirculation door actuator from the actuator
connector receptacle (Fig. 24).
(4) Remove the two screws that secure the recircu-
lation door actuator to the lower intake air housing.
(5) Remove the recirculation door actuator from
the lower intake air housing.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.(1) Position the recirculation door actuator onto
the lower intake air housing. If necessary, rotate the
actuator slightly to align the splines on the actuator
output shaft with those in the recirculation air door.
(2) Install and tighten the two screws that secure
the recirculation door actuator to the lower intake air
housing. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector
for the recirculation door actuator to the actuator
connector receptacle.
(4) Reposition the carpet on the passenger side
front floor back up to the dash panel.
(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).
Fig. 24 Recirculation Door Actuator
1 - LOWER INTAKE AIR HOUSING
2 - RECIRCULATION DOOR ACTUATOR
3 - HVAC WIRE HARNESS
4 - SCREW (2)
5 - LOWER EVAPORATOR HOUSING
24 - 28 CONTROLS - FRONTRS
RECIRCULATION DOOR ACTUATOR (Continued)
ProCarManuals.com

bezel with the snap clip receptacles on the retainer
above the headliner.
(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. Each
actuator 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
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

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-
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
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)
ProCarManuals.com

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.).
(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).
BLOWER MOTOR RELAY
DESCRIPTION
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
The blower motor relay (Fig. 5) is a International
Standards Organization (ISO) mini-relay. Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminalpatterns, 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 Intelligent 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
compressor clutch 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 factory-installed 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 (automatic heat-
er-A/C control). 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.
Fig. 5 Blower Motor Relay
24 - 32 CONTROLS - REARRS
BLEND DOOR ACTUATOR (Continued)
ProCarManuals.com

(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.).
(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 twointegral 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
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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