2004 CHRYSLER VOYAGER window

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING
SYSTEM REQUIREMENTS...............1
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
DESCRIPTION - SINGLE ZONE...........2
DESCRIPTION - DUAL ZONE.............2
DESCRIPTION - MANUAL THREE ZONE.....2
DESCRIPTION - AUTOMATIC THREE ZONE . . 3
OPERATION
OPERATION - HEATER AND AIR
CONDITIONER........................4
OPERATION - SINGLE ZONE.............4
OPERATION - DUAL ZONE...............5
OPERATION - MANUAL THREE ZONE......5
OPERATION - THREE ZONE ATC..........5DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C COOL
DOWN TEST..........................6
DIAGNOSIS AND TESTING - A/C
PERFORMANCE TEST..................7
DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST.................10
SPECIFICATIONS
A/C SYSTEM.........................11
CONTROLS - FRONT.....................14
CONTROLS - REAR......................34
DISTRIBUTION - FRONT...................43
DISTRIBUTION - REAR....................56
PLUMBING - FRONT.....................64
PLUMBING - REAR......................97
CABIN HEATER........................112
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the heating,
ventilation and air conditioning (HVAC) system, the
engine cooling system must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or condenser will
reduce the performance of the air conditioning and
engine cooling systems.
The engine cooling system includes the radiator,
thermostat, radiator hoses and the engine coolant
pump. Refer to Cooling for more information before
opening or attempting any service to the engine cool-
ing system.
DESCRIPTION - HEATER AND AIR
CONDITIONER
A manually controlled single zone type heating-air
conditioning system, manually controlled dual zone
type heating-air conditioning system, manually con-
trolled three zone type heating-air conditioning sys-
tem or an automatic controlled three zone typeheating-air conditioning system is available on this
model.
All vehicles are equipped with a common heater,
ventilation and air conditioning (HVAC) housing (Fig.
1). The system combines air conditioning, heating,
and ventilating capabilities in a single unit housing
mounted within the passenger compartment under
the instrument panel. The HVAC housing includes:
²Blower motor
²Blower motor resistor block or power module
(depending on application)
²Heater core
²Evaporator coil
²Blend door and actuator
²Mode door and actuator
²Recirculation door and actuator
Based upon the system and mode selected, condi-
tioned air can exit the HVAC housing through one or
a combination of the three main housing outlets:
defrost, panel or floor. The defrost and panel outlets
are located on the top of the housing and the floor
outlet is located on the bottom of the housing. Once
the conditioned air exits the unit housing, it is fur-
ther directed through molded plastic ducts to the var-
ious outlets in the vehicle interior. These outlets and
their locations are as follows:
²Defroster Outlet- A single large defroster out-
let is located in the center of the instrument panel
top cover, near the base of the windshield.
²Side Window Demister Outlets- There are
two side window demister outlets, one is located at
RSHEATING & AIR CONDITIONING24-1

each outboard end of the instrument panel, near the
A-pillars.
²Panel Outlets- There are five panel outlets in
the instrument panel, one located near each outboard
end of the instrument panel facing the rear of the
vehicle and three located near the top of the instru-
ment panel center bezel.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the center of
the floor panel near the dash panel.
DESCRIPTION - SINGLE ZONE
A single zone heating and air conditioning system
allows one temperature setting for the entire vehicle.
The full range of temperatures that the system can
produce are available by rotating the temperature
control located in A/C-heater control.
The A/C-heater control and integral computer is
located in the instrument panel and contains:
²a rear window defogger on/off switch. Contains
an LED that illuminates to show when the function
is operational.
²an air recirculation on/off switch. The Recircu-
late button contains an LED that illuminates to show
when the function is in operation.
²an air conditioning on/off switch. The Snowflake
button contains an LED that illuminates to shown
when the function is in operation.
²a rotary knob for fan speed selection and turn-
ing the heater-A/C system off.
²a rotary knob for temperature control of the dis-
charged air.
²a rotary knob for mode control.
DESCRIPTION - DUAL ZONE
The manual dual zone heating and air conditioning
system allows completely independent side-to-side
temperature control of the discharge air.
The A/C-heater control and integral computer is
located in the instrument panel and contains:
²a rear window defogger on/off switch. Contains
an LED that illuminates to show when the function
is operational.
²slide controls for completely independent side-to-
side temperature control of the discharged air. The
full range of temperature that the system can pro-
duce in any mode is available on either side of the
vehicle by independently positioning the slide con-
trols on the instrument panel.
²an air recirculation on/off switch. The Recircu-
late button contains an LED that illuminates to show
when the function is in operation.
²an air conditioning on/off switch. The Snowflake
button contains an LED that illuminates to shown
when the function is in operation.
²a rotary knob for fan speed selection and turn-
ing the heater-A/C system off.
²a rotary knob for mode control.
DESCRIPTION - MANUAL THREE ZONE
The fully adjustable manual three zone front and rear
heating and air conditioning system allows intermediate
seat passengers the ability to regulate air temperature
as well as fan speed and provides floor outlets to the
rear of the right sliding door and overhead outlets at
each rear outboard seating position. Primary control for
the rear blower is on the front A/C-heater control. All
controls are identified by ISO graphic symbols.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer
mounted in the instrument panel contains:
²a rear window defogger on/off switch.
²slide controls for completely independent side-to-
side temperature control of the discharge air. The full
range of temperature that the system can produce in
any mode is available on either side of the vehicle by
independently positioning the slide controls on the
instrument panel.
²an air recirculation button. The Recirculate but-
ton contains an LED that illuminates to show when
the function is in operation.
²an air conditioning button that allows the com-
pressor to be turned on/off. The Snowflake button
contains an LED that illuminates to shown when the
function is in operation.
²a rotary knob for front fan speed selection and
turning the heater-A/C system off.
²a rotary knob for rear fan speed selection.
²a rotary knob for mode control.
Fig. 1 HVAC Housing - LHD Shown, RHD Typical
1 - HVAC HOUSING
2 - BOLT
3 - BRACKET
4 - DASH PANEL
24 - 2 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

REAR CONTROL PANEL
The rear A/C-heater control centrally mounted in
the headliner allows intermediate seat passengers to
adjust rear air distribution, temperature and blower
motor speed when the center knob on the front A/C-
heater control is set to the Rear position. The rear
A/C-heater control contains:
²a rotary adjustment knob for temperature.
²a rotary adjustment for fan speed control.
DESCRIPTION - AUTOMATIC THREE ZONE
The automatic temperature control (ATC), three
zone, front and rear heating and air conditioning sys-
tem allows both the driver and front occupants and
the rear intermediate occupants to select individual
comfort temperatures.
NOTE: Individual comfort temperatures are the per-
ceived temperature level at the individual seating
areas, NOT the actual passenger compartment air
temperature.
The ATC system includes a particulate air filter.
The filter element is the same size as the air condi-
tioning evaporator to ensure ample capacity. A door
at the base of the HVAC housing below the glove box
provides easy access to the filter element.
The ATC computer utilizes integrated circuitry and
information carried on the programmable communi-
cations interface (PCI) data bus network to monitor
many sensors and switch inputs throughout the vehi-
cle. In response to those inputs, the internal circuitry
and programming of the ATC computer allow it to
control electronic functions and features of the ATC
system. The inputs to the ATC computer are:
²Vehicle Speed/Engine RPM± The ATC com-
puter monitors engine rpm, vehicle speed and mani-
fold absolute pressure information from the
powertrain control module (PCM).
²Coolant Temperature± ATC computer moni-
tors coolant temperature received from the PCM and
converts it to degrees Fahrenheit.
²Ambient Temperature± ATC computer moni-
tors ambient temperature from the compass mini trip
computer (CMTC) and converts it to degrees Fahren-
heit.
²Engine Miscellaneous Sensor Status±ATC
computer monitors A/C disable information from the
PCM.
²Refrigerant Pressure± ATC computer moni-
tors barometric pressure, intake air temperature,
high side pressure and methanol content as broad-
cast by the PCM.
²Door Ajar Status± The ATC computer moni-
tors driver front door, passenger front door, left rear
door, right rear door and liftgate ajar information, asidentified by the body control module (BCM), to
determine if all in-car temperatures should be main-
tained.
²Dimming± The ATC computer monitors dim-
ming status from the BCM to determine the required
level of brightness and will dim accordingly.
²Vehicle Odometer± The ATC computer moni-
tors the vehicle odometer information from the BCM
to prevent flashing the vacuum-flourescent (VF) dig-
ital display icons if the manual motor calibration or
manual cool down tests have failed. Flashing of the
display icons will cease when the vehicle odometer is
greater than 3 miles.
²English/Metric± The ATC computer monitors
the English/Metric information broadcast by the
CMTC. The set temp displays for both the front and
rear control heads will be set accordingly.
²Vehicle Identification Number± The ATC
computer monitors the last eight characters of the
VIN broadcast by the PCM and compares it to the
information stored in EEPROM. If it is different, the
new number will be stored over the old one and a
motor calibration shall be initiated.
²A/C System Information± The ATC computer
will send a message for evaporator temperature too
low, fan blower relay status, evaporator sensor fail-
ure, rear window defogger relay and A/C select.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer
is mounted in the instrument panel and contains:
²a power button which allows the system to be
completely turned off. The display is blank when the
system is off.
²a rocker switch that selects a cool-down rate.
LO-AUTO or HI-AUTO are displayed when the sys-
tem is in automatic operation.
²three rocker switches that select comfort temper-
atures from 15É to 30É C (59É to 85É F), which are
shown in the VF digital display. If the set temp is 15É
C (59É F) and the down button is pressed, the set
temp value will become 13É C (55É F) but the display
will show LO. If the set temp is 29É C (85É F) and the
up button is pressed, the set temp value will become
32É C (90É F) but the display will show HIGH. Tem-
peratures can be displayed in either metric or Fahr-
enheit, which is controlled from the overhead console.
²an air conditioning button that allows the com-
pressor to be turned off. A Snowflake symbol is illu-
minated when air conditioning is on, whether under
manual or automatic control.
²an air recirculation button. A Recirculation sym-
bol appears in the display when the button is
pressed, or when the system exceeds 80 percent cir-
culated air under automatic control due to high air
conditioning demand.
RSHEATING & AIR CONDITIONING24-3
HEATING & AIR CONDITIONING (Continued)

²a rear window defogger on/off switch. A graphic
symbol shows when the defroster is on.
²a rotary knob for front fan speed selection can
override the automatic controls. LEDs surrounding
the knob show the current setting.
²a rotary knob for control of the rear system.
²a rotary knob for mode control can override the
automatic controls. LEDs surrounding the knob show
the current setting.
²computer logic which remembers the settings of
the controls when the ignition is turned off and
retains those settings after a restart. If the system is
off when the ignition is turned off it will be off when
the engine is restarted, etc.
²computer logic which provides variable air recir-
culation under high temperature and humidity condi-
tions. Because recirculation is generally accompanied
by increased fan noise, the proportion of recirculated
to outside air gradually approaches full recirculation
over a broad temperature range.
²computer logic which enables additional heat for
diesel equipped vehicles by using a supplemental
engine coolant heater.
REAR CONTROL PANEL
A rear control panel centrally mounted on the
headliner includes a VF digital display, a rocker con-
trol for temperature and rotary controls for adjust-
ment of mode and fan speed of the rear heat and air
conditioning unit by intermediate seat passengers.
OPERATION
OPERATION - HEATER AND AIR CONDITIONER
The heating and air conditioning systems pulls
outside (ambient) air through the cowl opening at the
base of the windshield and into the plenum chamber
above the heating, ventilation and air conditioning
(HVAC) housing, then through the evaporator coil.
Air flow can be directed either through or around the
heater core by adjusting the blend door with the tem-
perature control knob on the A/C-heater control
located on instrument panel. The air flow can then
be directed out from the panel, floor and defrost out-
lets in various combinations using the mode control
knob located on the A/C-heater control. Air flow
velocity can be adjusted with the blower speed selec-
tor located on the
NOTE: It is important to keep the air intake opening
clear of debris. Leaf particles and other debris that
is small enough to pass through the cowl opening
screen can accumulate within the HVAC housing.
The closed, warm, damp and dark environment cre-
ated within the housing is ideal for the growth of
certain molds, mildews and other fungi. Any accu-mulation of decaying plant matter provides an addi-
tional food source for fungal spores, which enter
the housing with the fresh intake-air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during heater-A/C
operation if the air intake opening is not kept clear
of debris.
The heater and air conditioning system is a blend-
air type system. In a blend-air system, a blend door
controls the amount of conditioned air that is allowed
to flow through, or around, the heater core. The tem-
perature control knob determines the discharge air
temperature by actuating an electric motor, which
operates the blend door. This allows an almost imme-
diate control of the output air temperature of the sys-
tem.
On all models, the outside air intake can be shut
off by pressing the Recirculation button on the A/C-
heater control. This will operate a electric actuated
recirculation air door that closes off the outside fresh
air intake and recirculates the air that is already
inside the vehicle.
The air conditioning compressor can be engaged in
any mode by pressing the snowflake, A/C on/off but-
ton. It can also be engaged by placing the mode con-
trol in the mix to defrost positions. This will remove
heat and humidity from the air before it is directed
through or around the heater core. The mode control
knob on the A/C-heater control is used to also direct
the conditioned air to the selected system outlets.
The mode control switch uses an electric motor to
control the mode doors.OPERATION - SINGLE ZONE
²The temperature control knob enables continu-
ously variable proportioning of the conditioned air.
²The mode control knob enables continuously
variable proportioning of air flow between modes and
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position.
²When the heater-A/C system is off, the HVAC
computer closes the recirculation door to prevent out-
side air from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the A/C-
heater control.
²To reduce humidity for rapid defogging, the A/C
compressor runs automatically in modes from ªmixº
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off button.
24 - 4 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

OPERATION - DUAL ZONE
²The two slide controls enable continuously vari-
able proportioning of the conditioned air.
²The mode control knob enables continuously
variable proportioning of air flow between modes and
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position.
²When the heater-A/C system is off, the HVAC
computer closes the recirculation door to prevent out-
side air from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the A/C-
heater control.
²To reduce humidity for rapid defogging, the A/C
compressor runs automatically in modes from ªmixº
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off button.
OPERATION - MANUAL THREE ZONE
FRONT CONTROL PANEL
²Primary control of the rear heater-A/C system is
on the instrument panel. This control allows the
driver to set the rear compartment fan speed, to turn
the rear heater-A/C system off, or to give control to
the intermediate seat occupants by switching to the
Rear position. When the rear heater-A/C system is
controlled from the instrument panel, rear air tem-
perature is based on the driver-side temperature con-
trol position, and the mode (floor or overhead air) is
based on the front control's mode position.
²The mode control knob enables continuously
variable proportioning of air flow between modes but
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position. When the heater-A/C system is
off, the HVAC computer closes the recirculation door
to prevent outside air from entering the passenger
compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the control
panel.
²To reduce humidity for rapid defogging the A/C
compressor runs automatically in modes from ªmix'
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off, button.
REAR CONTROL PANEL
With the rear control active, temperature selection
dictates the air distribution mode (floor or overhead
air) of the rear unit: a cool temperature setting
directs flow to the overhead outlets and a warm tem-
perature setting to the floor.
OPERATION - THREE ZONE ATC
Comfort temperature or perceived temperature is
affected by air flow, sun levels on exposed skin, etc. The
air temperature may be higher or lower than the com-
fort temperature. Two infrared sensors in the instru-
ment panel center stack measure the temperature of
the occupants to determine their comfort level relative
to the selected comfort temperature. The integral
HVAC computer adjusts temperature and air flow rates
to maintain the customer-perceived comfort tempera-
ture. The air temperature in the passenger compart-
ment may be slightly higher or lower than the comfort
temperature at any time. For instance, on sunny sum-
mer days the air flow will probably be cooler than the
comfort temperature; on cold or cloudy days and at
night it will probably be slightly warmer. Infrared
Three-Zone Temperature Control provides side-to-side
and front-to-rear variations in comfort temperature set-
tings. The Infrared Three-Zone Automatic Temperature
Control fan provides a continuously variable air flow
rate to meet occupant comfort requirements.
FRONT CONTROL PANEL
²AUTO HI/LO± This system features two sets of
automatic control logic that allow either a rapid cool-
down rate or a somewhat slower cool-down rate with
less fan noise. HI-AUTO controls the system to reach
its assigned temperature quickly with a higher fan
speed. LO-AUTO controls the system to reach its
assigned temperature somewhat slower with less fan
noise. Both modes will automatically engage auto
recirculation.
²DE-FROST± The defrost function is active
when the rear window defogger function is active or
when the defog/defrost mode is selected.
²RECIRC± The RECIRC button will close the
air inlet door. If the system is in auto recirc (indica-
tor being displayed automatically), pressing the man-
ual recirc button will disable the auto recirc function
until one of the auto keys are pressed or the ignition
is cycled. If Auto HI/LO is pressed while manual
recirc is active, manual recirc will be deactivated.
²REAR WINDOW DEFOGGER± Pushing the
button sends a PCI bus message to the Intelligent
Power Module which controls the Rear Window
Defogger and side view mirror (if equipped) circuitry.
The defogger function will be active for 10 minutes
and can be turned off by a switch press. The defogger
will function while the control is in the ON mode.
RSHEATING & AIR CONDITIONING24-5
HEATING & AIR CONDITIONING (Continued)

required. If the test is failed, the snowflake icon and
the DELAY text will continue to blink across ignition
cycles until the vehicle has been driven for greater
than 1.6 km (8 miles).
DIAGNOSIS AND TESTING - A/C
PERFORMANCE TEST
The A/C system is designed to remove heat and
humidity from the air entering the passenger com-
partment. The evaporator, located in the HVAC hous-
ing, is cooled to temperatures near the freezing point.
As warm damp air passes over the fins in the A/C
evaporator, moisture in the air condenses to water,
dehumidifying the air. Condensation on the evapora-
tor fins reduces the evaporators ability to absorb
heat. During periods of high heat and humidity, an
A/C system will be less effective. With the instru-
ment control set to recirculation mode, only air from
the passenger compartment passes through the A/C
evaporator. As the passenger compartment air dehu-
midifies, A/C performance levels rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and tubing. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause of
trouble with the A/C system. The ambient air tem-perature in the location where the vehicle will be
tested must be a minimum of 21É C (70É F) for this
test.
PERFORMANCE TEST PROCEDURE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a tachometer and a manifold gauge
set.
(2) Set the mode control to the Recirculation Mode
position, the temperature control to the full cool posi-
tion and the blower to the highest speed position.
(3) Start the engine and hold at 1,000 rpm with
the A/C compressor clutch engaged.
(4) The engine should be warmed up to operating
temperature with the doors closed and windows
open.
(5) Insert a thermometer in the driver's side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) If the compressor clutch does not engage, pro-
ceed with diagnosis of the compressor clutch coil.
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS - FRONT/COMPRESSOR CLUTCH
COIL - DIAGNOSIS AND TESTING).
(7) With the A/C compressor clutch engaged, com-
pare the air temperature at the center panel outlet
and the compressor discharge pressure to the A/C
Performance Temperature and Pressure chart. The
compressor clutch may cycle, depending upon the
ambient temperature and humidity. If the clutch
cycles, use the readings obtained before the clutch
disengaged.
RSHEATING & AIR CONDITIONING24-7
HEATING & AIR CONDITIONING (Continued)

REMOVAL - MANUAL TEMPERATURE
CONTROL (MTC)
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Disconnect the wire harness connector from the
evaporator temperature sensor located on the top of
the HVAC housing (Fig. 18).
(4) Remove the evaporator temperature sensor
from the HVAC housing.
INSTALLATION
INSTALLATION - AUTOMATIC TEMPERATURE
CONTROL (ATC)
NOTE: Any grease removed with the evaporator
temperature sensor must be replaced. Failure to do
so could result in poor A/C performance.
(1) Position the evaporator temperature sensor
into the right rear corner of the engine compartment.
(2) Reconnect the wire harness connector to the
evaporator temperature sensor.
(3) Position the evaporator temperature sensor
onto the top of the expansion valve with the sensor
probe inserted into the well in the expansion valve.(4) Install the temperature sensor retainer.
(5) Install the window wiper module (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WIPER MOD-
ULE - INSTALLATION).
(6) Reinstall the air cleaner housing into the right
side of the engine compartment.
(7) Reconnect the battery negative cable.
(8) Run the HVAC Cool Down test to verify system
is operating properly (Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING).
INSTALLATION - MANUAL TEMPERATURE
CONTROL (MTC)
(1) Install the evaporator temperature sensor into
the top of the HVAC housing.
(2) Connect the wire harness connector to the
evaporator temperature sensor.
(3) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(4) Reconnect the negative battery cable.
INFRARED TEMPERATURE
SENSOR
DESCRIPTION
The infrared temperature sensor consists of two
infrared transducers that are concealed behind a
clear lens located near the bottom of the center panel
outlet near the top of the instrument panel center
bezel (Fig. 19). These sensors are used only on mod-
els equipped with the optional automatic tempera-
ture control (ATC) heating-A/C system. A molded
plastic connector receptacle on the bottom of the
panel outlet unit is concealed behind the center
bezel. A short, dedicated jumper wire harness routed
behind the center bezel connects the sensors directly
to the ATC A/C-heater control module near the bot-
tom of the center bezel. The infrared temperature
sensor is integral to the center bezel panel outlet
unit. The infrared sensors cannot be adjusted or
repaired and, if faulty or damaged, the center bezel
panel outlet unit must be replaced.
OPERATION
The dual infrared temperature sensors provide
independent measurement inputs to the Automatic
Temperature Control (ATC) heater-A/C control mod-
ule that indicates the surface temperature of the
driver seat and front seat passenger seat occupants.
By using a surface temperature measurement, rather
than an air temperature measurement, the ATC sys-
tem is able to adjust itself to the comfort level as per-
ceived by the occupant. This allows the system to
detect and compensate for other ambient conditions
Fig. 18 Evaporator Temperature Sensor - MTC
System
1 - EVAPORATOR TEMPERATURE SENSOR
2 - WIRE HARNESS CONNECTOR
3 - HVAC HOUSING
RSCONTROLS - FRONT24-29
EVAPORATOR TEMPERATURE SENSOR (Continued)

(5) Pull the air filter straight down and out of the
HVAC housing (Fig. 2).
INSTALLATION
(1) Note the ªAirflowº directional arrow imprinted
on the foam seal around the frame of the air filter.
This arrow should always be oriented towards the
center of the vehicle.
(2) With the air filter ªAirflowº arrow properly ori-
ented, carefully slide the filter fully upward into the
HVAC housing through the air filter opening.
(3) With the latch still positioned against its
opened stop, reinstall the air filter door onto the
lower HVAC housing air filter opening.
(4) Slide the air filter door latch toward the front
of the vehicle until it hits the closed stop on the door.
AIR OUTLETS
DESCRIPTION
Based upon the system mode selected, conditioned
air can exit the front HVAC housing through one or a
combination of the four main housing outlets: defrost,
demist, panel, or floor. Once the conditioned air exits
the unit housing, it is directed through molded plas-
tic ducts to the various outlets in the vehicle interior.
These outlets and their locations are as follows:
²Defroster Outlet- A single, centrally mounted
outlet delivers air for defrosting the large windshield.
Because outlet vanes are not needed to direct flow, a
simple, integral grid is molded into the center of the
instrument panel top cover to prevent objects from
falling into the duct. If the defroster outlet is faultyor damaged, the instrument panel top cover must be
replaced.
²Demister Outlets- There are two side window
demisters that aid in defogging and defrosting the
front door windows. One demister outlet is located at
each outboard end of the instrument panel top pad,
near the belt line at the A-pillars. The demister out-
lets can be removed from the top pad individually for
service replacement.
²Instrument Panel Outlets- There are five
panel outlets in the instrument panel, one located
near each outboard end of the instrument panel fac-
ing the rear of the vehicle, and three located near the
top of the instrument panel center bezel. On models
with manual temperature control, all five of these
outlets are fully adjustable. On models with Auto-
matic Temperature Control (ATC) system, the center
outlet in the center bezel has fixed vanes because it
also houses the remote infrared temperature sensors
for the front seat positions. The outboard outlets can
be removed individually for service replacement. The
center bezel outlets are serviced as a gang of three
outlets and, on models with ATC, also includes the
infrared sensors.
²Front Door Rear Outlets- A fully adjustable
outlet located at the rear of each front door trim
panel supplies only cooled air to the intermediate
seat passengers. Air is supplied to these outlets from
the instrument panel through ducts in the doors that
use molded seals at the instrument panel to prevent
air leakage. The door ducts are integral to the front
door trim panels. These outlets also incorporate a red
reflector to improve the safety and visibility of an
opened front door to traffic approaching the vehicle
from the rear at night. These outlets can be removed
from the door trim panels for service replacement.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the floor panel
center tunnel below the instrument panel. These out-
lets are integral to the front HVAC distribution hous-
ing.
²Rear Floor Outlets- Wide rear floor outlets
located under each front seat have integral, fixed
directional dividers to distribute heated air across
the floor for intermediate seat passengers. These out-
lets are integral to the floor distribution ducts routed
under the front floor carpet from an outlet nozzle on
the bottom of the front HVAC distribution housing.
REMOVAL
REMOVAL - CENTER BEZEL OUTLETS
The three outlets located near the top of the
instrument panel center bezel are serviced only as a
set of all three outlets. If the vehicle is equipped with
the optional automatic temperature control (ATC)
Fig. 2 Air Filter Door - Typical
1 - AIR FILTER DOOR
2-LATCH
3 - CLOSED STOP
4 - LOWER HVAC HOUSING
5 - OPENED STOP
24 - 44 DISTRIBUTION - FRONTRS
AIR FILTER (Continued)