instrument panel DODGE RAM 2002 Service Repair Manual

LOCATING VACUUM LEAKS
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 the vacuum harness connector
located between the a/c heater control and the HVAC
housing under the instrument panel.
(2) Connect the test set vacuum hose probe to each
port in the HVAC housing half of the vacuum har-
ness connector, one port at a time, and pause after
each connection (Fig. 2). The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty a/c
heater control. If not OK, go to step Step 3.(3) Determine the vacuum line color of the vacuum
circuit that is leaking. To determine the vacuum line
colors, see the Vacuum Circuits chart (Fig. 3).
(4) Disconnect and plug the vacuum line from the
component (fitting, actuator, valve, switch, or reser-
voir) on the other end of the leaking circuit. Instru-
ment panel disassembly or removal may be necessary
to gain access to some components. Refer to Instru-
ment Panel System for the procedures.
(5) Connect the test set hose or probe to the open
end of the leaking circuit. The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty
disconnected component. If not OK, go to Step 6.
(6) To locate a leak in a vacuum line, leave one
end of the line plugged and connect the test set hose
or probe to the other end of the line. Run your fin-
gers slowly along the line while watching the test set
gauge. The vacuum reading will fluctuate when your
fingers contact the source of the leak. To repair the
vacuum line, cut out the leaking section of the line.
Then, insert the loose ends of the line into a suitable
length of 3 millimeter (0.125 inch) inside diameter
rubber hose.
A/C COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a hub bearing and pul-
ley assembly, and a clutch plate (Fig. 4). The
electromagnetic coil unit and the hub bearing and
pulley assembly are each retained on the nose of the
compressor front housing with snap rings. The clutch
plate is mounted to the compressor shaft and secured
with a nut.
Fig. 2 VACUUM CIRCUIT TEST
BR/BECONTROLS 24 - 11
CONTROLS (Continued)

(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)
circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
open circuit to the fuse in the junction block as
required.
(5) The coil ground terminal cavity (85) is switched
to ground through the Powertrain Control Module
(PCM). There should be continuity between this cav-
ity and the A/C compressor clutch relay control cir-
cuit cavity of the PCM wire harness connector C
(gray) at all times. If not OK, repair the open circuit
as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 17).
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.(4) Unplug the compressor clutch relay from the
PDC and remove it.
INSTALLATION
(1) Install the compressor clutch relay by aligning
the relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
A/C-HEATER CONTROL
DESCRIPTION
Both the heater-only and a/c heater systems use a
combination of electrical and vacuum controls. These
controls provide the vehicle operator with a number
of setting options to help control the climate and
comfort within the vehicle. Refer to the owner's man-
ual in the vehicle glove box for more information on
the features, use, and suggested operation of these
controls.
OPERATION
The heater-only or a/c heater control panel is
located to the right of the instrument cluster on the
instrument panel. The control panel contains a rota-
ry-type temperature control knob, a rotary-type mode
control switch knob, and a rotary-type blower motor
speed switch knob. On models with the optional
heated mirror system, a momentary push button
switch and indicator lamp are located near the bot-
tom of the a/c heater control panel. Refer to Heated
Mirrors for more information on this feature.
The heater-only or a/c heater control panel cannot
be repaired. If faulty or damaged, the entire unit
must be replaced. The control knobs and the illumi-
nation lamps are available for service replacement.
DIAGNOSIS AND TESTING - A/C HEATER
CONTROL
Satisfactory heater and air conditioner perfor-
mance depends upon proper operation and adjust-
ment of all operating controls and refrigeration
system components. For circuit descriptions and dia-
grams, (Refer to Appropriate Wiring Information).
These inspections, tests, and adjustments should be
used to locate the cause of a malfunction.
Operation must be tested as described in the fol-
lowing sequence:
(1) Inspect and adjust the serpentine drive bel-
t(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - DIAGNOSIS AND TESTING).
(2) Start the engine and hold the idle speed at
1,300 rpm.
Fig. 17 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
24 - 18 CONTROLSBR/BE
A/C COMPRESSOR CLUTCH RELAY (Continued)

(3) On vehicles with air conditioning, turn the
temperature control knob to the extreme counter
clockwise (Cool) position, and set the mode control
switch knob to the Bi-Level (A/C) position. The out-
side (recirculation) air door should be open to outside
air. If not OK, (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS - DIAGNOSIS AND TEST-
ING - VACUUM SYSTEM).
(4) Open the vehicle windows. Test the blower
motor operation in all speeds. If not OK, (Refer to 24
- HEATING & AIR CONDITIONING/DISTRIBU-
TION/BLOWER MOTOR - DIAGNOSIS AND TEST-
ING).
(5) On vehicles with air conditioning, the compres-
sor should be running and the air conditioning sys-
tem in operation unless the ambient air temperature
is below about -1É C (30É F). If not OK, (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE).
(6) Check the mode control switch operation. The
heater and air conditioner systems should respond as
described in the owner's manual in the vehicle glove
box to each mode selected. Reduce the engine speed
to normal idle. The vacuum will be high at low idle
and the vacuum actuators should respond quickly. If
not OK, (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS - DIAGNOSIS AND TEST-
ING - VACUUM SYSTEM).
(7) If the vacuum tests, and the electrical compo-
nent and circuit tests reveal no problems, disassem-
ble the HVAC housing to inspect for mechanical
misalignment or binding of the mode doors (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION/HVAC HOUSING - DISASSEMBLY)
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) Reach under the instrument panel near the
driver side of the floor panel transmission tunnel andunplug the a/c heater control to HVAC housing vac-
uum harness connector.
(3) While still reaching under the instrument
panel, disengage the retainer on the a/c heater con-
trol half of the vacuum harness from the hole in the
center distribution duct (Fig. 18).
(4) Remove the cluster bezel from the instrument
panel(Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(5) Remove the four screws that secure the a/c
heater control to the instrument panel (Fig. 19).
(6) Pull the a/c heater control assembly away from
the instrument panel far enough to access the con-
nections on the back of the control.
(7) Unplug the wire harness connector from the
back of the a/c heater control.
(8) On vehicles with heated mirrors, unplug the
heated mirror wire harness connector from the back
of the a/c heater control.
(9) Remove the a/c heater control from the instru-
ment panel.
INSTALLATION
(1) Plug the wire harness connector(s) into the
receptacle(s) on the back of the a/c heater control.
(2) Route the HVAC vacuum harness through the
hole in the reinforcement below the a/c heater control
opening of the instrument panel.
(3) Position the a/c heater control in the instru-
ment panel and secure it with four screws. Tighten
the screws to 2.2 N´m (20 in. lbs.).
Fig. 18 A/C HEATER CONTROL VACUUM HARNESS
ROUTING
1 - A/C HEATER CONTROL VACUUM HARNESS
2 - REINFORCEMENT
3 - RETAINER
4 - CENTER DISTRIBUTION DUCT
BR/BECONTROLS 24 - 19
A/C-HEATER CONTROL (Continued)

(4) Reinstall the cluster bezel to the instrument
panel(Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(5) Reach under the instrument panel to reinstall
the a/c heater control vacuum harness retainer to the
side of the center distribution duct.
(6) Plug in the two halves of the a/c heater control
to HVAC housing vacuum harness connector.
(7) Connect the battery negative cable.
A/C HIGH PRESSURE SWITCH
DESCRIPTION
The a/c high pressure switch is located on the dis-
charge line near the compressor. The switch is
screwed onto a fitting that contains a Schrader-type
valve, which allows the switch to be serviced without
discharging the refrigerant system. The discharge
line fitting is equipped with an O-ring to seal the
switch connection.
OPERATION
The a/c high pressure switch is connected in series
electrically with the a/c low pressure switch between
ground and the Powertrain Control Module (PCM).
The switch contacts open and close causing the PCM
to turn the compressor clutch on and off. This pre-
vents compressor operation when the discharge line
pressure approaches high levels.
The a/c high pressure switch contacts are open
when the discharge line pressure rises above about3100 to 3375 kPa (450 to 490 psi). The switch con-
tacts will close when the discharge line pressure
drops to about 1860 to 2275 kPa (270 to 330 psi).
When checking refrigerant system pressures with a
manifold gauge set, keep in mind that the indicated
pressures will be about 172 kpa (25 psi) below the
actual switch pressure values due to the pressure
drop that occurs in the refrigerant system between
the switch and the high pressure service port.
The a/c high pressure switch is a factory-calibrated
unit. The switch cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C HIGH
PRESSURE SWITCH
Before performing diagnosis of the a/c high pres-
sure switch, verify that the refrigerant system has
the correct refrigerant charge. (Refer to 24 - HEAT-
ING & AIR CONDITIONING - DIAGNOSIS AND
TESTING)
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the a/c high pressure switch wire har-
ness connector from the switch on the refrigerant
system fitting.
(3) On the four terminal high pressure switch,
check for continuity between terminals C and D. On
the two terminal switch, check for continuity
between both terminals of the a/c high pressure
switch. There should be continuity. If OK, test and
repair the A/C switch sense circuit as required. If not
OK, replace the faulty switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the a/c
high pressure switch, which is mounted to a fitting
on the discharge line between the compressor and
the condenser inlet.
(3) Unscrew the a/c high pressure switch from the
discharge line fitting.
(4) Remove the a/c high pressure switch from the
vehicle.
(5) Remove the O-ring seal from the discharge line
fitting and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the discharge line fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle. (Refer to 24 - HEATING &
Fig. 19 A/C HEATER CONTROL REMOVE/INSTALL
1 - HEATED MIRROR WIRE HARNESS CONNECTOR
2 - WIRE HARNESS CONNECTOR
3 - SCREW
4 - HEATER-A/C CONTROL
24 - 20 CONTROLSBR/BE
A/C-HEATER CONTROL (Continued)

(1) The relay common feed terminal cavity (30) is
connected to fused battery feed directly from a fuse
in the Power Distribution Center (PDC), and should
be hot at all times. Check for battery voltage at the
PDC cavity for relay terminal 30. If OK, go to Step 2.
If not OK, repair the open circuit to the PDC fuse as
required.
(2) The relay normally closed terminal cavity (87A)
is not used for this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the blower motor. When the relay is
energized, terminal 87 is connected to terminal 30
and provides full battery current to the blower motor
feed circuit. There should be continuity between the
PDC cavity for terminal 87 and the blower motor
relay output circuit cavity of the blower motor wire
harness connector at all times. If OK, go to Step 4. If
not OK, repair the open circuit to the blower motor
as required.
(4) The coil battery terminal cavity (86) is con-
nected to the ignition switch. When the ignition
switch is placed in the On position, fused ignition
switch output is directed from a fuse in the junction
block to the relay electromagnetic coil to energize the
relay. There should be battery voltage at the PDC
cavity for relay terminal 86 with the ignition switch
in the On position. If OK, go to Step 5. If not OK,
repair the open circuit to the junction block fuse as
required.
(5) The coil ground terminal cavity (85) is con-
nected to ground. This terminal supplies the ground
for the relay electromagnetic coil. There should be
continuity between the PDC cavity for relay terminal
85 and a good ground at all times. If not OK, repair
the open circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 22).
(3) Refer to the label on the PDC for blower motor
relay identification and location.
(4) Unplug the blower motor relay from the PDC
and remove it.
INSTALLATION
(1) Install the blower motor relay by aligning the
relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
The blower motor resistor is mounted to the bot-
tom of the HVAC housing, under the instrument
panel and just inboard of the blower motor. It can be
accessed without removing any other components.
OPERATION
The resistor has multiple resistor wires, each of
which will change the resistance in the blower motor
ground path to change the blower motor speed. The
blower motor switch directs the ground path through
the correct resistor wire to obtain the selected blower
motor 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.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR BLOCK
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
Fig. 22 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
BR/BECONTROLS 24 - 23
BLOWER MOTOR RELAY (Continued)

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) Unplug the wire harness connector from the
blower motor resistor.
(3) Check for continuity between each of the
blower motor switch input terminals of the resistor
and the resistor output terminal. In each case there
should be continuity. If OK, repair the wire harness
circuits between the blower motor switch and the
blower motor resistor or blower motor as required. If
not OK, replace the faulty blower motor resistor.
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) Reach under the passenger side end of the
HVAC housing and unplug the wire harness connec-
tor from the blower motor resistor.
(3) Remove the screws that secure the blower
motor resistor to the HVAC housing.
(4) Remove the blower motor resistor from the
HVAC housing (Fig. 23).
INSTALLATION
(1) Install the blower motor resistor into the HVAC
housing and secure it with the mounting screws.
Tighten the mounting screws to 2.2 N´m (20 in. lbs.).
(2) Plug the wire harness connector into the
blower motor resistor.
(3) Connect the battery negative cable.
BLOWER MOTOR SWITCH
DESCRIPTION
The heater-only or a/c heater blower motor is con-
trolled by a four position rotary-type blower motor
switch, mounted in the HVAC control panel. The
switch allows the selection of one of four blower
motor speeds, but can only be turned off by selecting
the Off position with the heater-only or a/c heater
control switch knob.
OPERATION
The blower motor switch directs the blower motor
ground path through the mode control switch to the
blower motor resistor, or directly to ground, as
required to achieve the selected blower motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. The blower
motor switch knob is serviced separately.
Fig. 23 BLOWER MOTOR/RESISTOR
1 - BLOWER MOTOR
2 - BLOWER MOTOR RESISTOR
24 - 24 CONTROLSBR/BE
BLOWER MOTOR RESISTOR BLOCK (Continued)

DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
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 conti-
nuity. 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 unplugged, place the a/c heater mode control
switch knob 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 knob to each of the four speed
positions. There should be continuity at each driver
circuit terminal in only one blower motor switch
speed position. If OK, test and repair the blower
driver circuits between the a/c heater control connec-
tor and the blower motor resistor as required. If not
OK, replace the faulty a/c heater control unit.
REMOVAL
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL) The blower motor
switch knob is serviced separately.
BLEND DOOR ACTUATOR
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) Turn the ignition switch to the run position.
(2) Locate the temperature control knob in the mid
(12 o'clock) position.
(3) Turn the ignition switch to the off position.
(4) Disconnect and isolate the battery negative
cable.
(5) Remove the instrument panel from the vehi-
cle(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(6) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(7) Unplug the wire harness connector from the
blend door actuator (Fig. 24).
(8) Remove the two mounting screws which secure
the actuator to the housing.
(9) Slide the blend door actuator off the blend door
shaft.
NOTE: A black plastic coupler may be attached to
the blend door shaft. Remove the coupler and
inspect for damage. Reinstall if there is no damage
found.
INSTALLATION
NOTE: Before installing the blend door actuator, be
certain that the blend door is not binding and is
capable of full travel in both directions.
(1) Align the actuator with the blend door shaft
and rotate the actuator to align it to the mounting
bosses on the HVAC housing.
(2) Align and install the actuator screws. Tighten
the mounting screws to 2.2 N´m (20 in. lbs.).
(3) Plug in the wire harness connector to the blend
door actuator.
BR/BECONTROLS 24 - 25
BLOWER MOTOR SWITCH (Continued)

(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
(5) Install the instrument panel in the vehicle(Re-
fer to 23 - BODY/INSTRUMENT PANEL/INSTRU-
MENT PANEL ASSEMBLY - INSTALLATION).
(6) Make sure the Temperature Control Knob is in
the mid (12 o'clock) position to allow the actuator to
automatically position itself in the mid position and
come to a complete stop when powered up.
(7) Connect the battery negative cable.
MODE DOOR ACTUATOR
REMOVAL - HEAT/DEFROST DOOR ACTUATOR
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 ACCIDENTALAIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the HVAC housing from the vehicle
and place it on a work bench. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL)
(3) Unplug the two vacuum harness connectors
from the heat/defrost door actuator (Fig. 25).
(4) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the heat/defrost door
crank arm off the heat/defrost door pivot.
(5) Remove the two screws that secure the heat/de-
frost door actuator to the HVAC housing.
(6) Remove the heat/defrost door actuator from the
HVAC housing.
REMOVAL - PANEL/DEFROST DOOR
ACTUATOR
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.
Fig. 24 BLEND DOOR ACTUATOR REMOVE/
INSTALL
1 - DUCT
2 - MOUNTING SCREWS
3 - UNIT HOUSING
4 - HARNESS AND CONNECTOR
5 - BLEND DOOR ACTUATOR
Fig. 25 HEAT/DEFROST DOOR ACTUATOR
1 - VACUUM LINE
2 - DOOR PIVOT CONNECTION
3 - HEAT/DEFROST DOOR ACTUATOR
24 - 26 CONTROLSBR/BE
BLEND DOOR ACTUATOR (Continued)

(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel assembly from
the vehicle(Refer to 23 - BODY/INSTRUMENT PAN-
EL/INSTRUMENT PANEL ASSEMBLY - REMOV-
AL).
(3) Unplug the vacuum harness connector from the
panel/defrost door actuator (Fig. 26).
(4) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the panel/defrost door
crank arm off the panel/defrost door pivot.
(5) Remove the two screws that secure the panel/
defrost door actuator to the HVAC housing.
(6) Remove the panel/defrost door actuator from
the HVAC housing.
INSTALLATION - HEAT/DEFROST DOOR
ACTUATOR
NOTE: Before installing the heat/defrost door actua-
tor, be certain that the heat/defrost door is not bind-
ing.
(1) Install the heat/defrost door actuator from the
HVAC housing. Tighten the actuator mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Carefully snap the heat/defrost door crank arm
on the heat/defrost door pivot.(3) Plug in the two vacuum harness connectors to
the heat/defrost door actuator.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
(5) Connect the battery negative cable.
INSTALLATION - PANEL/DEFROST DOOR
ACTUATOR
NOTE: Before installing the panel/defrost door
actuator, be certain that the panel/defrost door is
not binding.
(1) Install the panel/defrost door actuator on the
HVAC housing. Tighten the mounting screws to 2.2
N´m (20 in. lbs.).
(2) Carefully snap the panel/defrost door crank
arm on the panel/defrost door pivot.
(3) Plug the vacuum harness connector to the pan-
el/defrost door actuator.
(4) Install the instrument panel assembly in the
vehicle(Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL ASSEMBLY - INSTALLA-
TION).
(5) Connect the battery negative cable.
RECIRCULATION DOOR
ACTUATOR
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 glove box from the instrument pan-
el(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
Fig. 26 PANEL/DEFROST DOOR ACTUATOR
1 - VACUUM LINE
2 - PANEL/DEFROST ACTUATOR
3 - SHAFT RETAINER
BR/BECONTROLS 24 - 27
MODE DOOR ACTUATOR (Continued)

(3) Reach through the glove box opening to access
and unplug the vacuum harness connector from the
recirculation door actuator (Fig. 27).
(4) Loosen the two nuts that secure the recircula-
tion door actuator to the mounting bracket on the
HVAC housing.
(5) Slide the two actuator mounting studs out of
the slots in the actuator mounting bracket.
(6) Pull the recirculation door actuator downward
far enough to access the clip that retains the actua-
tor link to the recirculation door lever.
(7) Unsnap the clip from the recirculation door
actuator link and disengage the link from the recir-
culation door lever.
(8) Remove the recirculation door actuator from
the HVAC housing.
INSTALLATION
NOTE: When reinstalling the recirculation door
actuator, insert a screwdriver or another suitable
tool through the recirculation air intake grille to
prop the recirculation air door up in the open posi-
tion far enough to access the recirculation air door
lever through the instrument panel glove box open-
ing.NOTE: Before installing the blend door actuator, be
certain that the blend door is not binding.
(1) Snap the clip on the recirculation door actuator
link to engage the link to the recirculation door lever.
(2) Slide the two actuator mounting studs into the
slots in the actuator mounting bracket.
(3) Install the two nuts that secure the recircula-
tion door actuator to the mounting bracket on the
HVAC housing. Tighten the mounting nuts until the
recirculation air door actuator is seated to the
mounting bracket.
(4) Plug in the vacuum harness connector to the
recirculation door actuator.
(5) Install the glove box in the instrument panel-
(Refer to 23 - BODY/INSTRUMENT PANEL/GLOVE
BOX - INSTALLATION).
(6) Connect the battery negative cable.
VACUUM CHECK VALVE
DESCRIPTION
On models with a gasoline engine, a vacuum check
valve is installed in the accessory vacuum supply line
near the vacuum tap on the right side of the engine
intake manifold. On models with a diesel engine, a
vacuum check valve is installed on the engine vac-
uum pump. The vacuum check valve is designed to
allow vacuum to flow in only one direction through
the accessory vacuum supply circuits.
OPERATION
The use of a vacuum check valve helps to maintain
the system vacuum needed to retain the selected
HVAC mode and vehicle speed control settings. On
gasoline engine models, it prevents the engine from
bleeding down system vacuum through the intake
manifold during extended heavy engine load (low
engine vacuum) operation. On diesel engine models,
it prevents oil from contaminating the vacuum sup-
ply system by maintaining vacuum in the pump after
the engine is shut-off.
On gasoline engine models, a second vacuum check
valve is installed in the accessory vacuum supply line
at the tee fitting near the dash panel in the engine
compartment. This check valve also helps to main-
tain the system vacuum needed to retain the selected
HVAC mode settings, but isolates the HVAC vacuum
circuit from the vehicle speed control vacuum circuit.
It prevents the vehicle speed control servo from
bleeding down the HVAC system vacuum during
extended heavy engine load operation.
The vacuum check valve cannot be repaired and, if
faulty or damaged, it must be replaced.
Fig. 27 RECIRCULATION DOOR ACTUATOR
1 - DOOR SHAFT RETAINER
2 - RECIRCULATING AIR DOOR
3 - ROD CLIP
4 - BLOWER MOTOR ELECTRICAL CONNECTOR
5 - ACTUATOR
6 - BLOWER MOTOR
7 - VACUUM LINE
24 - 28 CONTROLSBR/BE
RECIRCULATION DOOR ACTUATOR (Continued)