Motor mount DODGE RAM 1500 1998 2.G Manual Online

The panel outlets receive airflow from the HVAC
housing through a molded plastic main panel duct,
center panel duct and two end panel ducts. The two
end panel ducts direct airflow to the left and right
instrument panel outlets, while the center panel duct
directs airflow to the two center panel outlets. Each
of these outlets can be individually adjusted to direct
the flow of air.
The floor outlets receive airflow from the HVAC
housing through the floor distribution duct. The front
floor outlets are integral to the molded plastic floor
distribution duct, which is secured to the bottom of
the housing. The floor outlets cannot be adjusted.
The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a fixed
orifice tube in the liquid line near the condenser out-
let tube to meter refrigerant flow to the evaporator
coil. To maintain minimum evaporator temperature
and prevent evaporator freezing, a evaporator tem-
perature sensor is used. The JTEC control module is
programmed to respond to the evaporator tempera-
ture sensor input by cycling the air conditioning com-
pressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to remove
heat and humidity from the air entering the passen-
ger compartment. The evaporator, located in the
HVAC housing, is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins in the evaporator, moisture in the air condenses
to water, dehumidifying the air. Condensation on the
evaporator fins reduces the evaporators ability to
absorb heat. During periods of high heat and humid-
ity, an air conditioning system will be less effective.
With the instrument control set to Recirculation
mode, only air from the passenger compartment
passes through the evaporator. As the passenger com-
partment air dehumidifies, 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 air condition-
ing system. When humidity is high, the evaporator
has to perform a double duty. It must lower the air
temperature, and it must lower the temperature ofthe moisture in the air that condenses on the evapo-
rator fins. Condensing the moisture in the air trans-
fers heat energy into the evaporator fins and tubing.
This reduces the amount of heat the evaporator can
absorb from the air. High humidity greatly reduces
the ability of the evaporator to lower the temperature
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
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
PERFORMANCE TEST PROCEDURE
Review Safety Warnings and Cautions before per-
forming this procedure (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION). Air temperature in test
room and on vehicle must be 21É C (70É F) minimum
for this test.
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
or A/C recycling/charging station.
(2) Set the A/C-heater mode control in the Recircu-
lation Mode position, the temperature control knob in
the full cool position, and the blower motor switch 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 side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.
(7) With the compressor clutch engaged, record the
discharge air temperature and the compressor dis-
charge pressure.
(8) If the discharge air temperature fails to meet
the specifications in the A/C Performance Tempera-
ture chart, refer to the Pressure Diagnosis chart.
DRHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)

²Faulty A/C-heater control.
²Faulty related wiring harness or connectors.
²Improper engine coolant temperature.
SPECIFICATIONS - A/C SYSTEM
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood Specifica-
tion Label.
A/C SYSTEM SPECIFICATION CHART
Item Description Notes
Compressor Saden SD-7
(5.9L engine)SP-15 PAG oil
Denso 10S17
(3.7L/4.7L/5.7L
engines)ND-8 PAG oil
Freeze±up
ControlEvaporator
Temperature
SensorEvaporator coil
mounted
High psi Control A/C pressure
transducerDischarge line
mounted
Compressor
Clutch Coil
Draw2 - 3.9 amps @
12V   0.5V @
21É C (70É F)5.9L engine
2.2 amps @
12V   0.5V @
21É C (70É F)3.7L/4.7L/5.7L
engines
Compressor
Clutch Air Gap0.41 - 0.79 mm
(0.016 - 0.031
in.)5.9L engine
0.35 - 0.65 mm
(0.013 - 0.025
in.)3.7L/4.7L/5.7L
engines
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft Nut 15-20 11-15 ±
A/C Compressor Bolt-Inner
Front-3.7L,4.7L40 30 ±
A/C Compressor Bolt-Inner
Rear-3.7L,4.7L55 41 ±
A/C Compressor Rear Bolt-
3.7L,4.7L55 41 ±
A/C Compressor Lower Bolts-5.7L 40 30 ±
A/C Compressor Rear Bolt-5.7L 55 41 ±
A/C Compressor Bolts-5.9L Diesel 24 17 ±
A/C Compressor Clutch Coil Wire
Retainer Screw2.2 ± 20
A/C-Heater Control Screws 2.2 ± 20
Accumulator Bracket Bolts 4.5 ± 40
Blower Motor Screws 2.2 ± 20
Blower Motor Resistor Block
Screws2.2 ± 20
Center Distribution Duct Screws 2.2 ± 20
DRHEATING & AIR CONDITIONING 24 - 7
HEATING & AIR CONDITIONING (Continued)

and coil are the only serviced parts on the compres-
sor.
A/C compressor clutch engagement is controlled by
several components: the A/C-heater control, A/C pres-
sure transducer, A/C compressor clutch relay, evapo-
rator temperature sensor and the powertrain control
module (PCM). The PCM may delay compressor
clutch engagement for up to thirty seconds (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the A/C-heater controls in any A/C mode,
and the blower motor switch in the lowest speed
position, start the engine and run it at normal idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of thecompressor clutch circuit and PCM control. The fol-
lowing components must be checked and repaired as
required before you can complete testing of the clutch
coil:
²Fuses in the junction block and the power distri-
bution center (PDC)
²A/C-heater control
²A/C compressor clutch relay
²A/C pressure transducer
²Evaporator temperature sensor
²Powertrain control module (PCM)
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is within
specifications with the electrical system voltage at
11.5 to 12.5 volts (Refer to 24 - HEATING & AIR
CONDITIONING - SPECIFICATIONS). This should
only be checked with the work area temperature at
21É C (70É F). If system voltage is more than 12.5
volts, add electrical loads by turning on electrical
accessories until the system voltage drops below 12.5
volts.
(a) If the clutch coil current reading is above
specifications, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
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
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.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, rotor, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Disconnect the compressor clutch coil wire har-
ness connector.
(4) Remove the bolts that secure the compressor to
the mounting bracket.
(5) Remove the compressor from the mounting
bracket. Support the compressor in the engine com-
partment while servicing the clutch.
Fig. 1 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (not used on KJ)
3 - ROTOR
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 10 CONTROLSDR
A/C COMPRESSOR CLUTCH/COIL (Continued)

The illumination lamps are available for service
replacement.
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.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL).
(3) Remove the screws that secure the A/C-heater
control to the instrument panel (Fig. 14).
INSTALLATION
(1) Position the A/C-heater control onto the instru-
ment panel center bezel and install the retaining
screws. Tighten the screws to 2.2 N´m (20 in. lbs.).
(2) Install the instrument panel center bezel (Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL CENTER BEZEL - INSTALLATION).
(3) Reconnect the battery negative cable.
A/C PRESSURE TRANSDUCER
DESCRIPTION
The A/C pressure transducer is a switch that is
installed on a fitting located on the refrigerant dis-
charge line between the compressor and the con-
denser in the front corner of the engine
compartment. An internally threaded hex fitting on
the transducer connects it to the externally threaded
Schrader-type fitting on the discharge line. A rubber
O-ring seals the connection between the transducer
and the discharge line fitting. Three terminals within
a molded plastic connector receptacle on the top of
the transducer connect it to the vehicle electrical sys-
tem through a wire lead and connector of the head-
lamp and dash wire harness.
Fig. 12 Single Zone HVAC Control
1 - MOUNTING TAB (4)
2 - A/C BUTTON
3 - SIDEVIEW MIRROR DEFROSTER BUTTON (IF EQUIPED)
4 - MODE CONTROL SWITCH
5 - TEMPERATURE CONTROL SWITCH
6 - BLOWER MOTOR SWITCH
Fig. 13 Dual Zone A/C Control
1 - A/C BUTTON
2 - MAX. A/C BUTTON
3 - SIDEVIEW MIRROR DEFROSTER BUTTON (IF EQUIPED)
4 - MOUNTING TABS (4)
5 - DRIVERSIDE TEMPERATURE CONTROL
6 - PASSENGERSIDE TEMPERATURE CONTROL
7 - MODE CONTROL SWITCH
8 - BLOWER MOTOR SWITCH
Fig. 14 A/C-Heater Control - Typical, Rear View
1 - MOUNTING TAB (4)
2 - SCREW (4)
3 - A/C-HEATER CONTROL ELECTRICAL CONNECTOR
4 - HEATED SIDEVIEW MIRROR ELECTRICAL CONNECTOR
5 - A/C-HEATER CONTROL
DRCONTROLS 24 - 15
A/C HEATER CONTROL (Continued)

(4) Reconnect the battery negative cable.
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 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 doors, which are controlled by two blend
door actuators. The single zone blend door actuator is
located on the driver side end of the HVAC housing,
close to the dash panel. In the dual zone system, the
same blend door actuator used for the single zone
system becomes the driver side blend door actuator,
and is mechanically connected to only the driver side
blend door. In the dual zone system, a second sepa-
rate blend door actuator is also located on the top of
the HVAC housing and is mechanically connected to
only the passenger side blend door.
The blend door actuators are interchangeable with
each other, as well as with the actuators for the
mode door, defrost door and the recirculation door.
Each actuator is contained within an identical blackmolded plastic housing with an integral wire connec-
tor receptacle. Integral mounting tabs allow the
actuator to be secured with three screws to the
HVAC housing. Each actuator also has an identical
output shaft with splines that connects it to the link-
age that drives the proper door. The blend door
actuators do not require mechanical indexing to the
blend door linkage, as they are electronically cali-
brated by the heater-A/C control module. The blend
door actuators cannot be adjusted or repaired and, if
damaged or faulty, they must be replaced.
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 con-
nection 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 operation and relative positions of the blend
door actuator and the blend-air door. The A/C-heater
control learns the 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.
Fig. 15 A/C Pressure Transducer - 3.7L Shown
1 - NUT
2 - FRONT UPPER CROSSMEMBER
3 - A/C CONDENSER
4 - NUT (2)
5 - SUCTION LINE
6 - A/C COMPRESSOR
7 - A/C PRESSURE TRANSDUCER
8 - WIRE HARNESS CONNECTOR
9 - A/C DISCHARGE LINE
DRCONTROLS 24 - 17
A/C PRESSURE TRANSDUCER (Continued)

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 instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Disconnect the wire harness connector from the
blend door actuator(s) (Fig. 16).
(4) Remove the screws that secure the blend door
actuator(s) to the HVAC housing.
(5) Remove the blend door actuator(s) from the
HVAC housing.INSTALLATION
(1) Position the blend door actuator(s) into the
HVAC housing. If necessary, rotate the actuator(s)
slightly to align the splines on the actuator output
sleeve(s) with those on the blend door linkage.
(2) Install and tighten the screws that secure the
blend door actuator(s) to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the HVAC wire harness connector to
the blend door actuator(s).
(4) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(5) Reconnect the battery negative cable.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
The blower motor resistor is mounted to the bot-
tom side of the HVAC housing near the blower motor.
It can be accessed for service from underneath the
instrument panel.
OPERATION
The resistor has multiple resistor wires, each of
which will reduce the current flow to the blower
motor to change the blower motor speed by changing
the resistance in the blower motor ground path. The
blower motor switch directs the ground path 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. When
the blower motor switch is in the highest speed posi-
tion, the blower motor resistor is bypassed and the
blower motor receives a direct path to ground.
The blower motor resistor cannot be repaired and,
if faulty or damaged, it must be replaced.
Fig. 16 HVAC Housing - Dual Zone Shown, Single
Zone Typical
1 - NUT
2 - PASSENGER BLEND DOOR ACTUATOR
3 - NUT
4 - INLET BAFFLE
5 - RECIRCULATION DOOR ACTUATOR
6 - RECIRCULATION DOOR
7 - DRIVER SIDE BLEND DOOR ACTUATOR
8 - HVAC HOUSING
9 - BOLT
10 - DEFROSTER DOOR ACTUATOR
11 - MODE DOOR ACTUATOR
24 - 18 CONTROLSDR
BLEND DOOR ACTUATOR (Continued)

BLOWER MOTOR SWITCH
DESCRIPTION
The blower motor is controlled by a rotary-type
blower motor switch, mounted in the A/C-heater con-
trol. The switch allows the selection of one of four
different blower motor speeds and includes an Off
position.
OPERATION
The blower motor switch provides a blower motor
ground path through the A/C-heater mode control
switch. The blower motor switch directs this ground
path through or around the blower motor resistor
wires, as required to achieve the selected blower
motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire A/C-heater control
must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
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.
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.
(1) Check for battery voltage at the fuse in the
Power Distribution Center (PDC). 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 Off position.
Disconnect and isolate the battery negative cable.
Remove the A/C-heater control from the instrument
panel (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS/A/C HEATER CONTROL -
REMOVAL). Check for continuity between the
ground circuit cavity of the A/C-heater control wire
harness connector and a good ground. There should
be continuity. If OK, go to Step 3. If not OK, repair
the open circuit to ground as required.
(3) With the A/C-heater control wire harness con-
nector disconnected, place the A/C-heater mode con-
trol switch in any position except the Off position.
Check for continuity between the ground circuit ter-
minal and each of the blower motor driver circuit ter-
minals of the A/C-heater control as you move the
blower motor switch to each of the four speed posi-
tions. There should be continuity at each driver cir-
cuit terminal in only one blower motor switch speed
position. If OK, test and repair the blower driver cir-
cuits between the A/C-heater control connector and
the blower motor resistor as required. If not OK,
replace the faulty A/C-heater control.
DEFROST DOOR ACTUATOR
DESCRIPTION
The defrost door actuator is a reversible, 12-volt
Direct Current (DC), servo motor. The defrost door
actuator is located on the driver side end of the
HVAC housing, underneath the instrument panel
and is mechanically connected to the defroster door.
The defrost door actuator is interchangeable with
the actuators for the mode door, blend door(s) and
the recirculation door. Each actuator is contained
within an identical black molded plastic housing with
an integral wire connector receptacle. Integral
mounting tabs allow the actuator to be secured with
three screws to the HVAC housing. Each actuator
also has an identical output shaft with splines that
connects it to the linkage that drives the proper door.
The defrost door actuator does not require mechani-
Fig. 18 A/C-Heater Control - Single Zone Shown,
Dual Zone Typical
1 - MOUNTING TAB (4)
2 - A/C BUTTON
3 - SIDEVIEW MIRROR DEFROSTER BUTTON (IF EQUIPED)
4 - MODE CONTROL SWITCH
5 - TEMPERATURE CONTROL SWITCH
6 - BLOWER MOTOR SWITCH
24 - 20 CONTROLSDR

(2) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Connect the HVAC wire harness connector to
the evaporator temperature sensor.
(4) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
(5) Reconnect the battery negative cable.
MODE DOOR ACTUATOR
DESCRIPTION
The mode door actuator is a reversible 12-volt
Direct Current (DC) servo motor. The mode door
actuator is located on the HVAC housing, behind the
instrument panel and is mechanically connected to
the mode door.
The mode door actuator is interchangeable with
the actuators for the blend door(s), defrost door and
the recirculation door. Each actuator is contained
within an identical black molded plastic housing with
an integral wire connector receptacle. Integral
mounting tabs allow the actuator to be secured with
three screws to the HVAC housing. Each actuator
also has an identical output shaft with splines that
connects it to the linkage that drives the proper door.
The mode door actuator does not require mechanical
indexing to the mode door linkage, as it is electroni-
cally calibrated 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 A/C-
heater control through the vehicle electrical system
by a dedicated two-wire lead and connector from the
HVAC wire harness. The mode door actuator can
move the mode 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 mode door will move in one direction. When the
A/C-heater control reverses the polarity of the volt-
age to the motor, the mode door moves in the oppo-
site direction. When the A/C-heater control makes
the voltage to both connections high or both connec-
tions low, the mode door stops and will not move.
These same motor connections also provide a feed-
back signal to the A/C-heater control. This feedback
signal allows the A/C-heater control to monitor the
operation and relative position of the mode door
actuator and the mode door. The A/C-heater control
learns the mode door stop positions during the cali-
bration procedure and will store a diagnostic troublecode (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 Body Diagnostic Proce-
dures for more information. The mode door actuator
cannot be adjusted or repaired and, if damaged or
faulty, it 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.
(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) Disconnect the wire harness connector from the
mode door actuator (Fig. 22).
(4) Remove the screws that secure the mode door
actuator to the HVAC housing.
(5) Remove the mode door actuator from the HVAC
housing.
INSTALLATION
(1) Position the mode door actuator onto the HVAC
housing. If necessary, rotate the actuator slightly to
align the splines on the actuator output sleeve with
those on the mode door linkage.
(2) Install and tighten the screws that secure the
mode door actuator to the HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(3) Connect the HVAC wire harness connector to
the mode door actuator.
(4) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(5) Reconnect the battery negative cable.
DRCONTROLS 24 - 23
EVAPORATOR TEMPERATURE SENSOR (Continued)

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 top of the
air inlet housing. The recirculation door actuator is
mechanically connected to the recirculation air door.
The recirculation door actuator is interchangeable
with the actuators for the blend door(s), defrost door
and the mode door. Each actuator is contained within
an identical black molded plastic housing with an
integral wire connector receptacle. Integral mounting
tabs allow the actuator to be secured with three
screws to air inlet housing. Each actuator also has an
identical output shaft with splines that connects it tothe linkage that drives the proper door. The recircu-
lation door actuator does not require mechanical
indexing to the recirculation door linkage, as it is
electronically calibrated by the heater-A/C control
module. The recirculation door actuator cannot be
adjusted or repaired and, if damaged or faulty, it
must be replaced.
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.
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.
Fig. 22 HVAC Housing - Dual Zone Shown, Single
Zone Typical
1 - NUT
2 - PASSENGER BLEND DOOR ACTUATOR
3 - NUT
4 - INLET BAFFLE
5 - RECIRCULATION DOOR ACTUATOR
6 - RECIRCULATION DOOR
7 - DRIVER SIDE BLEND DOOR ACTUATOR
8 - HVAC HOUSING
9 - BOLT
10 - DEFROSTER DOOR ACTUATOR
11 - MODE DOOR ACTUATOR
24 - 24 CONTROLSDR
MODE DOOR ACTUATOR (Continued)

DISASSEMBLY
(1) Remove the HVAC housing from the vehicle
and place it on the workbench (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL).
(2) Disconnect the electrical connectors from the
blower motor, blower motor resistor block, evaporator
temperature sensor and each actuator (Fig. 10).
(3) Remove the HVAC wiring harness from the
HVAC housing.
(4) If necessary, remove the blower motor from
the HVAC housing (Refer to 24 - HEATING & AIR
CONDITIONING/DISTRIBUTION/BLOWER
MOTOR - REMOVAL).
(5) If necessary, remove the blower motor resistor
block from the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - REMOVAL).
(6) Carefully remove the foam seals from the
heater core and evaporator coil tube mounting flange
of the HVAC housing. If the either seal is deformed
or damaged, it must be replaced.
(7) Remove the screws that secure the heater core
in the HVAC housing and carefully remove the
heater core from the housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/HEATER
CORE - REMOVAL).(8) Use a screwdriver to pry off the four snap clips
that help secure the upper and lower HVAC housing
halves together.
(9) Remove the screws that secure the upper and
lower HVAC housing halves to each other and those
that secure the recirculation housing to the upper
HVAC housing.
(10) Carefully separate the recirculation housing
and the upper HVAC housing from the lower hous-
ing.
ASSEMBLY
(1) Position the upper HVAC housing to the lower
housing. During assembly, be certain of the following:
(a) That each of the door pivot shaft ends are
properly engaged in there pivot holes.
(b) That the evaporator drain opening is clean
and the drain foam seal is properly installed.
(2) Install the screws and snap clips that secure
the upper and lower HVAC housing halves to each
other and those that secure the recirculation housing
to the upper HVAC housing. Tighten the screws to
2.2 N´m (20 in. lbs.).
(3) Install the foam seals on the heater core and
evaporator coil tubes.
(4) If removed, install the blower motor resistor
block (Refer to 24 - HEATING & AIR CONDITION-
Fig. 10 HVAC Housing - Disassembled
1 - RECIRCULATION HOUSING
2 - RECIRC DOOR ACTUATOR
3 - DRIVER SIDE BLEND DOOR ACTUATOR
4 - FLOOR DISTRIBUTION DUCT
5 - DEFROST DOOR ACTUATOR
6 - PANEL DOOR ACTUATOR
7 - UPPER HVAC HOUSING
8 - PASSENGER SIDE BLEND DOOR ACTUATOR9 - HEATER CORE
10 - LOWER HVAC HOUSING
11 - HVAC WIRE HARNESS
12 - DRAIN FOAM SEAL
13 - BLOWER MOTOR
14 - EVAPORATOR FOAM SEAL
15 - EVAPORATOR
16 - HEATER CORE FOAM SEAL
DRDISTRIBUTION 24 - 35
HVAC HOUSING (Continued)