1998 DODGE RAM 1500 Steering column

DEFROSTER DUCT
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.(1) Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(2) Disconnect the wire harness connector from the
center radio speaker (Fig. 7).
(3) Position the speaker wire harness connector
out of the way.
(4) Remove the screw that secures the defroster
duct adapter to the instrument panel support.
(5) Remove the defroster duct adapter from the
defroster duct.
(6) Remove the six screws that secure the
defroster duct to the instrument panel.
(7) Remove the defroster duct from the instrument
panel.
INSTALLATION
(1) Install the defroster duct into the instrument
panel.
(2) Install the six screws that secure the defroster
duct to the instrument panel. Tighten the screws to
2.2 N´m (20 in.lbs.).
(3) Install the defroster duct adapter onto the
defroster duct.
(4) Install the screw that secures the defroster
duct adapter to the instrument panel support.
Tighten the screw to 2.2 N´m (20 in.lbs.).
(5) Connect the wire harness connector to the cen-
ter radio speaker.
(6) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
Fig. 6 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 - 32 DISTRIBUTIONDR
DEFROST DOOR (Continued)

FLOOR DISTRIBUTION DUCT
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove the HVAC housing from the vehicle
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(2) Remove the screws that secure the floor distri-
bution duct to the bottom of the HVAC housing.
(3) Remove the floor distribution duct from the
HVAC housing.
Fig. 7 Defroster Duct
1 - SPEAKER WIRE HARNESS CONNECTOR
2 - DEFROSTER DUCT SCREWS (6)
3 - DEFROSTER DUCT ADAPTER4 - DEFROSTER DUCT ADAPTER SCREW
5 - DEFROSTER DUCT
Fig. 8 Floor Distribution Duct
1 - FLOOR DISTRIBUTION DUCT
2 - HVAC HOUSING
3 - SCREWS (5)
DRDISTRIBUTION 24 - 33
DEFROSTER DUCT (Continued)

INSTALLATION
(1) Install the floor distribution duct onto the bot-
tom of the HVAC housing.
(2) Install the five screws that secure the floor dis-
tribution duct to the HVAC housing. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(3) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
HVAC HOUSING
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.
NOTE: The HVAC housing must be removed from
the vehicle and the two halves of the housing sep-
arated for service access of the heater core, evap-
orator coil, defrost door, blend door(s) and the
recirculation door.
(1) Disconnect and isolate the battery negative
cable.
(2) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(3) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(4) Disconnect the liquid refrigerant line fitting
from the evaporator inlet tube (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/REFRIG-
ERANT LINE COUPLER - REMOVAL). Discard the
O-ring seal and install plugs in, or tape over the
opened liquid refrigerant line fitting and evaporator
inlet tube.
(5) Remove the accumulator (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/ACCU-
MULATOR - REMOVAL). Discard the O-ring seals
and install plugs in, or tape over the opened refrig-
erant line fittings and evaporator outlet tube.(6) Disconnect the heater hoses from the heater
core tubes. Install plugs in, or tape over the opened
heater core tubes.
(7) Remove the powertrain control module (PCM)
from the engine compartment to gain access to the
HVAC housing retaining nuts (Refer to 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/POWER-
TRAIN CONTROL MODULE - REMOVAL).
(8) Remove the two nuts from the HVAC housing
mounting studs in the engine compartment.
(9) Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL -
REMOVAL).
(10) Remove the bolt that secures the HVAC hous-
ing to the floor bracket located in the center of the
vehicle (Fig. 9).
(11) Remove the two nuts from the HVAC housing
mounting studs in the passenger compartment.
(12) Remove the HVAC housing from inside the
vehicle. Take care not to allow any remaining coolant
to drain onto the vehicles interior.
Fig. 9 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 - 34 DISTRIBUTIONDR
FLOOR DISTRIBUTION DUCT (Continued)

ING/CONTROLS/BLOWER MOTOR RESISTOR
BLOCK - INSTALLATION).
(5) If removed, install the blower motor (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION/BLOWER MOTOR - INSTALLATION).
(6) Install the HVAC wire harness. Make sure the
wires are routed through all wiring retainers.
(7) Connect the wire harness to the blower motor,
blower motor resistor block, evaporator temperature
sensor and each actuator.
(8) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
INSTALLATION
WARNING: IF THE VEHICLE IS EQUIPPED WITH AIR
CONDITIONING, REVIEW THE WARNINGS AND
CAUTIONS IN PLUMBING BEFORE PERFORMING
THE FOLLOWING OPERATION. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - WARNING)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION -
REFRIGERANT HOSES/LINES/TUBES PRECAU-
TIONS)
(1) Position the HVAC housing into the vehicle. Be
certain that the evaporator condensate drain tube
and the housing mounting studs are inserted into
their correct locations.
(2) Install the two nuts that secure the HVAC
housing to the mounting studs in the passenger com-
partment. Tighten the nuts to 6.2 N´m (55 in. lbs.).
(3) Install the bolt that secures the HVAC housing
to the floor bracket in the passenger compartment.
Tighten the bolt to 6.2 N´m (55 in. lbs.).
(4) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL - INSTALLATION).
(5) Install the two nuts that secure the HVAC
housing to the mounting studs in the engine com-
partment. Tighten the nuts to 6.2 N´m (55 in. lbs.).
(6) Install the powertrain control module (PCM)
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/POWERTRAIN CONTROL MOD-
ULE - INSTALLATION).
(7) Unplug or remove the tape from the heater
core tubes and connect the heater hoses to the heater
core tubes.
(8) Unplug or remove the tape from the opened
refrigerant line fittings and the evaporator outlet
tube and install the accumulator (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/AC-
CUMULATOR - INSTALLATION).
(9) Unplug or remove the tape from the liquid line
and the evaporator inlet tube fittings. Connect the
liquid line coupler to the evaporator inlet tube (Referto 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - A/C LINE COU-
PLERS).
(10) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(11) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(12) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE - STANDARD PROCEDURE).
(13) Connect the battery negative cable.
(14) Start the engine and check for proper opera-
tion of the heating and air conditioning systems.
INSTRUMENT PANEL
DEMISTER DUCTS
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) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(2) Remove the two screws that secure the center
distribution duct to the instrument panel support.
(3) Remove the center distribution duct from
instrument panel support, panel ducts and demister
ducts.
(4) Remove the right side panel duct adapter (Fig.
11).
(5) Remove the right side intermediate demister
duct.
(6) Remove the left side intermediate demister
duct.
(7) Remove the left side panel duct adapter.
(8) Remove the instrument panel cover (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL).
24 - 36 DISTRIBUTIONDR
HVAC HOUSING (Continued)

(9) Remove the screws that secure the left and
right side panel ducts to the instrument panel.
(10) Remove the left and right side panel ducts
from the instrument panel.
(11) Remove the screws that secure the left and
right side demister ducts to the instrument panel.
(12) Remove the left and right side demister ducts
from the instrument panel.
INSTALLATION
(1) Install the left and right side demister ducts to
the instrument panel.
(2) Install the screws that secure the left and right
side demister ducts to the instrument panel. Tighten
the screws to 2.2 N´m (20 in. lbs.).
(3) Install the left and right side panel ducts to the
instrument panel.
(4) Install the screws that secure the left and right
side panel ducts to the instrument panel. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(5) Install the instrument panel top cover (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION).
(6) Install the left side panel duct adapter.
(7) Install the left side intermediate demister duct.
(8) Install the right side intermediate demister
duct.
(9) Install the right side panel duct adapter.
(10) Install the center distribution duct to the
instrument panel support.(11) Install the two screws that secure the center
distribution duct to the instrument panel support.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(12) Install the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - INSTALLATION).
INSTRUMENT PANEL DUCTS
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) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(2) Remove the two screws that secure the center
distribution duct to the instrument panel support.
(3) Remove the center distribution duct from
instrument panel support, panel ducts and demister
ducts.
(4) Remove the right side panel duct adapter (Fig.
12).
(5) Remove the right side intermediate demister
duct.
(6) Remove the left side intermediate demister
duct.
(7) Remove the left side panel duct adapter.
(8) Remove the instrument panel cover (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL).
(9) Remove the screws that secure the left and
right side panel ducts to the instrument panel.
(10) Remove the left and right side panel ducts
from the instrument panel.
INSTALLATION
(1) Install the left and right side panel ducts to the
instrument panel.
(2) Install the screws that secure the left and right
side panel ducts to the instrument panel. Tighten the
screws to 2.2 N´m (20 in. lbs.).
Fig. 11 Instrument Panel Demister Ducts
1 - RIGHT SIDE PANEL DUCT
2 - RIGHT SIDE PANEL DUCT ADAPTER
3 - RIGHT SIDE INTERMEDIATE DEMISTER DUCT
4 - LEFT SIDE INTERMEDIATE DEMISTER DUCT
5 - LEFT SIDE PANEL DUCT
6 - LEFT SIDE PANEL DUCT ADAPTER
DRDISTRIBUTION 24 - 37
INSTRUMENT PANEL DEMISTER DUCTS (Continued)

(3) Install the instrument panel top cover (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION).
(4) Install the left side panel duct adapter.
(5) Install the left side intermediate demister duct.
(6) Install the right side intermediate demister
duct.
(7) Install the right side panel duct adapter.
(8) Install the center distribution duct to the
instrument panel support.
(9) Install the two screws that secure the center
distribution duct to the instrument panel support.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(10) Install the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - INSTALLATION).
MODE DOOR
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) Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(2) Remove the mode door actuator and sleeve
from the upper half of the HVAC housing (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS/
MODE DOOR ACTUATOR - REMOVAL).
(3) Remove the two screws that secure the mode
door adapter to the top the HVAC housing (Fig. 13).
(4) Disconnect the two plastic retainer clips that
secure the mode door adapter to the front the HVAC
housing and remove the mode door adapter.
(5) Remove the screws that secure the two mode
door spring retainers to the top the HVAC housing
and remove the retainers.
(6) Remove the mode door cover from the top the
HVAC housing.
(7) Gently slide the mode door toward the outside
of the housing. Tilt and lift the door out of the hous-
ing.
(8) Inspect the mode door, seals and the HVAC
housing for damage or binding and repair or replace
components as required.
INSTALLATION
(1) Position the mode door pivot shaft into the
pivot hole in the upper half of the HVAC housing.
(2) Install the mode door by carefully tipping the
door into the HVAC housing, then sliding the door
into it's operating position.
(3) Install the mode door cover onto the top the
HVAC housing.
(4) Install the screws that secure the mode door
spring retainers to the top the HVAC housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(5) Install the mode door adapter to the top the
HVAC housing. Connect the two plastic retainer clips
Fig. 12 Instrument Panel Ducts
1 - RIGHT SIDE PANEL DUCT
2 - RIGHT SIDE PANEL DUCT ADAPTER
3 - RIGHT SIDE INTERMEDIATE DEMISTER DUCT
4 - LEFT SIDE INTERMEDIATE DEMISTER DUCT
5 - LEFT SIDE PANEL DUCT
6 - LEFT SIDE PANEL DUCT ADAPTER
24 - 38 DISTRIBUTIONDR
INSTRUMENT PANEL DUCTS (Continued)

that secure the mode door adapter to the front the
HVAC housing.
(6) Install the two screws that secure the mode
door adapter to the top of the HVAC housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(7) Install the mode door actuator and sleeve to
the upper half of the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/
MODE DOOR ACTUATOR - INSTALLATION).
(8) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
RECIRCULATION DOOR
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) 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) Remove the recirculation door actuator from
the recirculation housing (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/RECIRCULA-
TION DOOR ACTUATOR - REMOVAL).
(3) Remove the two screws and disengage the two
plastic retaining tabs that secure the recirculation
housing to the HVAC housing (Fig. 14).
(4) Remove the recirculation housing from the
HVAC housing.
(5) Gently slide the recirculation door toward the
outside of the recirculation housing. Tilt and lift the
door out of the housing.
(6) Inspect the recirculation door, seals and the
HVAC recirculation housing for damage or binding
and repair or replace components as required.
Fig. 13 HVAC Mode Door
1 - MODE DOOR ADAPTER
2 - SPRING RETAINER
3 - SCREW (2)
4 - MODE DOOR ACTUATOR
5 - MODE DOOR
DRDISTRIBUTION 24 - 39
MODE DOOR (Continued)

REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
A/C evaporator (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/HVAC HOUSING -
DISASSEMBLY).
(3) Remove the evaporator temperature sensor
probe from the A/C evaporator.
(4) Lift the A/C evaporator out of the HVAC hous-
ing (Fig. 19).
INSTALLATION
NOTE: If the A/C evaporator is being replaced, add
60 milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Install the A/C evaporator into the HVAC hous-
ing. Make sure that the evaporator drain is clean
and unrestricted and that the evaporator deflector
shield is installed.
(2) Install the evaporator temperature sensor
probe into the A/C evaporator.
(3) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(4) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
A/C ORIFICE TUBE
DESCRIPTION
The fixed A/C orifice tube (Fig. 20) is installed in
the liquid line between the outlet of the condenser
and the inlet of the evaporator. The A/C orifice tube
is only serviced as an part of the liquid line.
OPERATION
The fixed A/C orifice tube is used to meter the flow
of liquid refrigerant into the evaporator coil. The
high-pressure liquid refrigerant from the condenser
expands into a low-pressure liquid as it passes
through the metering orifice and diffuser screen of
the A/C orifice tube.
The A/C orifice tube is not serviceable. The A/C ori-
fice tube cannot be repaired and, if faulty or plugged,
it must be replaced as part of the liquid line.
Fig. 19 A/C Evaporator - Typical
1 - PASSENGER SIDE BLEND DOOR LEVER
2 - PASSENGER SIDE BLEND DOOR
3 - EVAPORATOR TEMPERATURE SENSOR WIRE
4 - HVAC HOUSING
5 - A/C EVAPORATOR
6 - EVAPORATOR TEMPERATURE SENSOR PROBE
7 - DRIVER SIDE BLEND DOOR
8 - DRIVER SIDE BLEND DOOR LEVER
Fig. 20 Fixed A/C Orifice Tube - Typical
1 - DIFFUSER SCREEN
2 - O-RING SEALS
3 - INLET FILTER SCREEN
4 - ORIFICE
24 - 60 PLUMBINGDR
A/C EVAPORATOR (Continued)