(6) Install the screw that secures the front of the
rear HVAC housing to the right quarter inner panel.
Tighten the screw to 11 N´m (97 in. lbs.).
(7) Install the screw that secures the back of the
rear HVAC housing to the right D-pillar. Tighten the
screw to 11 N´m (97 in. lbs.).
(8) Install the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel. Tighten the screws to 2 N´m (17 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
The rear blower motor relay is a International
Standards Organization (ISO)-type relay (Fig. 4).
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The rear
blower motor relay is located in the integrated power
module (IPM) in the engine compartment. See the
fuse and relay map on the inner surface of the cover
of the IPM for rear blower motor relay identification
and location.
The black, molded plastic case is the most visible
component of the rear 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 rear blower motor relay cannot be adjusted or
repaired. If the relay is damaged or faulty, it must be
replaced.
OPERATION
The rear blower motor relay is an electromechani-
cal switch that uses a low current input from the
Front Control Module (FCM) to control the high cur-
rent output to the rear blower motor resistor (man-
ual heater-A/C control) or rear blower motor power
module (ATC heater-A/C control). The movable com-
mon feed contact point is held against the fixed nor-
mally closed contact point by spring pressure. When
the relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. The
resistor or diode is connected in parallel with the
relay coil in the relay, and helps to dissipate voltage
spikes and electromagnetic interference that can be
generated as the electromagnetic field of the relay
coil collapses.
The rear blower motor 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 rear 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.
Fig. 4 Rear Blower Motor Relay
24 - 36 CONTROLS - REARRS
BLEND DOOR ACTUATOR (Continued)
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
(ATC heater-A/C control) through a fuse in the IPM
on the fused rear blower motor relay output circuit
only when the blower motor relay coil is energized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the rear blower
motor relay coil is de-energized.
Refer to the appropriate wiring information for
diagnosis and testing of the micro-relay and for com-
plete HVAC wiring diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the integrated power
module (IPM) (Fig. 5).
NOTE: Refer to the fuse and relay map on the inner
surface of the cover of the IPM for rear blower
motor relay identification and location.
(3) Remove the rear blower motor relay from the
IPM.
INSTALLATION
NOTE: Refer to the fuse and relay map on the inner
surface of the cover of the integrated power module
(IPM) for rear blower motor relay identification and
location.
(1) Position the rear blower motor relay to the
proper receptacle in the IPM.
(2) Align the rear blower motor relay terminals
with the terminal cavities in the IPM receptacle.
(3) Push down firmly on the rear blower motor
relay until the terminals are fully seated in the ter-
minal cavities.
(4) Install the cover onto the IPM.
(5) Reconnect the negative battery cable.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
A rear blower motor resistor is used on this model
when it is equipped with the manual heater-A/C sys-
tem. Models equipped with the optional Automatic
Temperature Control (ATC) system use a rear blower
motor power module, instead of the blower motor
resistor block (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS/POWER MODULE -
DESCRIPTION). The rear blower motor resistor
block is mounted to the rear HVAC housing, directly
above the expansion valve. The resistor block con-
sists of a molded plastic mounting plate with an inte-
gral connector receptacle. Concealed behind the
mounting plate is an electrical circuit board with two
resistors and a thermal fuse. The rear blower motor
resistor block is accessed for service by removing the
right quarter and D-pillar trim panels.
OPERATION
The rear blower motor resistor block is connected
to the vehicle electrical system through a dedicated
take out and connector of the rear HVAC wire har-
ness. The blower motor resistor has an electrical cir-
cuit board with two resistors, 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 rear blower motor through the
correct resistor to obtain the selected speed.
Fig. 5 Rear Blower Motor Relay
1 - INTEGRATED POWER MODULE (IPM)
2 - REAR BLOWER MOTOR RELAY
3 - FRONT CONTROL MODULE (FCM)
RSCONTROLS - REAR24-37
BLOWER MOTOR RELAY (Continued)
(10) Remove the rear mode door actuator from
between the rear HVAC housing and the quarter
inner panel.
INSTALLATION
(1) Position the mode door actuator between the
rear HVAC housing and the quarter inner panel.
(2) Reconnect the rear HVAC wire harness connec-
tor to the rear mode door actuator.
(3) Position the rear mode door actuator onto the
rear HVAC 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 the two screws that secure the rear
mode door actuator to the rear HVAC housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Push the top of the rear HVAC housing back
into position against the right quarter inner panel.
(6) Install the screw that secures the front of the
rear HVAC housing to the right quarter inner panel.
Tighten the screw to 11 N´m (97 in. lbs.).(7) Install the screw that secures the back of the
rear HVAC housing to the right D-pillar. Tighten the
screw to 11 N´m (97 in. lbs.).
(8) Install the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel. Tighten the screws to 2 N´m (17 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 - REAR
BLOWER MOTOR
DESCRIPTION
A rear blower motor power module is used on this
model when it is equipped with the optional Auto-
matic Temperature Control (ATC) system. Models
equipped 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 rear blower motor power module is installed in
the back of the rear HVAC housing, directly above
the expansion valve. The module 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
power module is accessed for service by removing the
right quarter and D-pillar trim panels.
OPERATION
The rear blower motor power module is connected
to the vehicle electrical system through a dedicated
take out and connector of the rear HVAC wire har-
ness. A second connector receptacle receives the pig-
tail wire connector from the rear blower motor. The
rear blower motor power module allows the micropro-
cessor-based Automatic 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 pro-
gramming 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
Fig. 7 Rear HVAC Blend Door Actuator
1 - SCREW (2)
2 - MODE DOOR ACTUATOR
3 - SCREW (2)
4 - CONNECTOR
5 - BLEND DOOR ACTUATOR
6 - WIRE HARNESS CONNECTOR
24 - 40 CONTROLS - REARRS
MODE DOOR ACTUATOR - REAR (Continued)
resulting output drives the power module circuitry,
which adjusts the voltage output received from the
rear blower motor relay to change or maintain the
desired blower speed. The rear blower motor power
module is diagnosed using a DRBIIItscan tool. Refer
to Body Diagnostic Procedures.
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 from the rear blower motor power module
(Fig. 8).
(4) Disconnect the rear blower motor pigtail wire
connector from the rear blower motor power module.
(5) Remove the two screws that secure the rear
blower motor power module to the rear HVAC hous-
ing.
(6) Remove the rear blower motor power module
from the rear HVAC housing.
INSTALLATION
(1) Position the rear blower motor power module
into the rear HVAC housing.
(2) Install the two screws that secure the rear
blower motor power module to the rear HVAC hous-
ing. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the rear blower motor pigtail wire to
the rear blower motor power module.
(4) Connect the rear HVAC wire harness connector
to the rear blower motor power module.
(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. 8 Rear Blower Motor Power Module
1 - REAR HVAC HOUSING
2 - SCREW (2)
3 - D-PILLAR
4 - REAR BLOWER MOTOR PIGTAIL WIRE
5 - REAR HVAC WIRE HARNESS
6 - EXPANSION VALVE
7 - REAR BLOWER MOTOR POWER MODULE
RSCONTROLS - REAR24-41
POWER MODULE - REAR BLOWER MOTOR (Continued)
whenever the ignition switch is in the On position
and the A/C-heater control power is turned on.
The blower motor receives battery current when-
ever the front blower motor relay is energized. The
front blower motor relay output circuit is protected
by a fuse in the Integrated Power Module (IPM)
located in the engine compartment near the battery.
In the manual heater-A/C 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 motor
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 are
used to control the velocity of air moving through the
HVAC housing by spinning the blower wheel within
the housing at the selected speed or, in the ATC sys-
tem, at the selected or programmed speed.
DIAGNOSIS AND TESTING
FRONT 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.
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.BLOWER MOTOR ELECTRICAL DIAGNOSIS
(1) Check the fuse (Fuse 10 - 40 ampere) in the
Integrated 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 A/C-heater 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, check the front blower motor relay.
(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 block (Manual
Temperature Control) or the front blower motor
power module (Automatic Temperature Control) from
the resistor or module connector receptacle. Recon-
nect the battery negative cable. Turn the ignition
switch to the On position. Be certain that the A/C-
heater 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 connec-
tor for the front blower motor resistor block (MTC) or
the front blower motor 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.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the front blower motor pigtail wire con-
nector from the connector receptacle of the front
blower motor resistor block (MTC) or the front
blower motor power module (ATC). Use jumper wires
to connect a battery and ground feeds to the blower
motor pigtail wire connector. The blower motor
should operate. If OK with MTC, proceed to diagno-
sis of the front blower motor resistor block (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/BLOWER MOTOR RESISTOR - DIAGNO-
SIS AND TESTING). If OK with ATC, use a DRBIII
scan tool to diagnose the front blower motor power
module. Refer to Body Diagnostic information. If not
OK with MTC or ATC, replace the faulty front blower
motor.
BLOWER MOTOR NOISE OR VIBRATION
Refer to the Blower Motor Noise/Vibration Diagno-
sis chart for basic checks of the blower motor when a
vibration or noise is present (Fig. 7).
24 - 46 DISTRIBUTION - FRONTRS
BLOWER MOTOR (Continued)
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY OR DEATH.
NOTE: The blower motor is located on the passen-
ger side of the vehicle under the instrument panel.
The blower motor can be removed from the vehicle
without having to remove the HVAC housing.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
REMOVAL).
(3) Pull back the carpet to access the front upper
screw that secures the air inlet housing.
(4) Remove the recirculation door actuator (Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS - FRONT/RECIRCULATION DOOR ACTUA-
TOR - REMOVAL).
(5) Remove the recirculation door actuator wire
lead from the routing clip located on the lower air
inlet housing and position the wire lead aside.
(6) Disconnect the blower motor wire lead connec-
tor from the blower motor resistor block or power
module, depending on application.
(7) Remove the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing (Fig. 8).
(8) Remove the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing.
(9) Push the rubber blower motor wire lead grom-
met through the opening in the lower air inlet hous-
ing (Fig. 9).
(10) Feed the blower motor wire lead through the
opening in the lower air inlet housing and remove
the lower air inlet housing from the vehicle.(11) Position the recirculation-air door as neces-
sary to access and remove the three screws that
secure the blower motor to the lower half of the
HVAC housing.
Fig. 8 Lower Air Inlet Housing
1 - BLOWER MOTOR RESISTOR BLOCK/POWER MODULE
2 - BLOWER MOTOR WIRE LEAD
3 - LOWER HVAC HOUSING
4 - UPPER AIR INLET HOUSING
5 - UPPER SCREW (1)
6 - LOWER AIR INLET HOUSING
7 - RECIRCULATION DOOR ACTUATOR
8 - ACTUATOR WIRE LEAD
9 - LOWER SCREW (4)
Fig. 9 Blower Motor Wire Lead Grommet
1 - BLOWER MOTOR WIRE LEAD GROMMET
24 - 48 DISTRIBUTION - FRONTRS
BLOWER MOTOR (Continued)
(12) Gently flex the recirculation air door far down
enough to remove the blower motor and wheel from
the HVAC housing.
(13) Remove the blower motor and wheel from the
HVAC housing. Note the position of the blower motor
mounting tabs (Fig. 10).
INSTALLATION
(1) Position the blower motor and wheel to the
lower half of the HVAC housing. Align the blower
motor mounting tabs to the correct location on the
HVAC housing.
(2) Gently flex the recirculation-air door far down
enough to install the blower motor and wheel into
the HVAC housing.
(3) Position the recirculation-air door as necessary
to install the three screws that secure the blower
motor to the HVAC housing. Tighten the screws to 2
N´m (17 in. lbs.).
(4) Feed the blower motor wire lead through the
opening in the lower air inlet housing and seat the
rubber grommet into the lower air inlet housing.
(5) Position the recirculation-air door pivot into
the lower air inlet housing.
(6) Install the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(7) Install the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing. Tighten the screws to 2 N´m (17 in.
lbs.).
(8) Connect the blower motor wire lead connector
to the blower motor resistor block or power module,
depending on application.(9) Install the recirculation door actuator (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/RECIRCULATION DOOR ACTUATOR -
INSTALLATION).
(10) Install the recirculation door actuator wire
lead into the routing clip located on the lower air
inlet housing.
(11) Reinstall the carpet.
(12) Install the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
INSTALLATION).
(13) Reconnect the negative battery cable.
(14) 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).
DEFROSTER DUCT
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 instrument panel from the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the fasteners that secure the defroster
duct to the instrument panel armature.
(5) Remove the defroster duct from the instrument
panel.Fig. 10 Blower Motor Mounting Tabs
1 - BLOWER MOTOR
2 - RUBBER GROMMET
3 - BLOWER MOTOR CONNECTOR
4 - MOUNTING TABS
RSDISTRIBUTION - FRONT24-49
BLOWER MOTOR (Continued)
DISTRIBUTION DUCT
REMOVAL
(1) Remove the trim from the right quarter inner
panel and the right D pillaR (Refer to 23 - BODY/IN-
TERIOR/RIGHT QUARTER TRIM PANEL -
REMOVAL).
(2) Slide the rear distribution duct upwards far
enough to disengage it from the outlet at the top of
the rear HVAC housing (Fig. 2).
(3) While pulling the lower end of the rear distri-
bution duct away from the rear HVAC housing out-
let, disengage the upper end of the distribution duct
from the headliner duct.
(4) Remove the rea distribution duct from the
vehicle.
INSTALLATION
(1) Align the upper end of the rear distribution
duct to the headliner duct.
(2) Slide the upper end of the rear distribution
duct onto the headliner duct far enough to align the
lower end of the duct with the outlet at the top of the
rear HVAC housing.
(3) Slide the rear distribution duct downwards far
enough to engage it onto the outlet at the top of the
rear HVAC housing.
(4) Reinstall the trim onto the right quarter inner
panel and the right D pillar (Refer to 23 - BODY/IN-
TERIOR/RIGHT QUARTER TRIM PANEL -
INSTALLATION).
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. The blower motor
and wheel are located near the top of the rear HVAC
housing in the passenger compartment behind the
right rear wheel house. The rear HVAC housing must
be removed from the vehicle to access the blower
motor for service. 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
On models equipped with the Manual Temperature
Control (MTC) system, the rear blower motor will
operate only whenever the ignition switch is in the
On position, the front blower control switch is in any
position except Off and the rear blower control switch
on the front A/C-heater control is in any position
except Off. On models equipped with the Automatic
Temperature Control (ATC) system, the blower motor
will operate whenever the ignition switch is in the
On position, the A/C-heater control power is turned
on and the rear blower control switch on the front
A/C-heater control is in any position except Off. The
rear blower motor can only be turned off by turning
off the rear system at the front A/C-heater control.
The rear blower motor receives battery current
whenever the rear blower motor relay is energized.
The rear blower motor relay output circuit is pro-
tected by a fuse in the Integrated Power Module
(IPM) located in the engine compartment near the
battery. In the MTC system, the rear 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 rear blower
motor speed is controlled by an electronic blower
motor power module, which uses a pulse width mod-
ulated input from the ATC control module and feed-
back from the rear blower motor to regulate the
blower motor ground path it provides. The rear
blower motor and wheel are used to control the veloc-
ity of air moving through the rear HVAC housing.
The rear blower motor controls the velocity of the air
flowing through the rear HVAC housing by spinning
the blower wheel within the housing at the selected
speed or, in the ATC system, at the selected or pro-
grammed speed.
Fig. 2 Rear Distribution Duct
1 - HEADLINER DUCT
2 - REAR DISTRIBUTION DUCT
3 - REAR HVAC HOUSING OUTLET
RSDISTRIBUTION - REAR24-57