Motor mount DODGE RAM 1500 1998 2.G Manual PDF

OPERATION
During normal vehicle operation, the Transfer Case
Control Module (TCCM) monitors the mode sensor
outputs at least every 250 (+/-50) milliseconds when
the shift motor is stationary and 400 microseconds
when the shift motor is active. A mode sensor signal
between 3.8 Volts and 0.8 Volts is considered to be
undefined.
Refer to SECTOR ANGLES vs. TRANSFER CASE
POSITION for the relative angles of the transfer case
shift sector versus the interpreted transfer case gear
operating mode. Refer to MODE SENSOR CHAN-
NEL STATES for the sensor codes returned to the
TCCM for each transfer case mode sensor position.The various between gears positions can also be
referred as the transfer case's coarse position. These
coarse positions come into play during shift attempts.
SECTOR ANGLES VS. TRANSFER CASE POSITION
Shaft Angle (Degrees) Transfer Case Position
+40 4LO
+20 N
0 2WD/AWD
-20 4HI
MODE SENSOR CHANNEL STATES
Transfer Case
Angle (degrees)Sensor Channel A Sensor Channel B Sensor Channel C Sensor Channel D
Between Gears H H L H
+40 (4LO) H H L L
Between Gears H H L H
Between Gears H L L H
+20 (NEUTRAL) H L L L
Between Gears H L L H
Between Gears H L H H
0 (2WD/AWD) H L H L
Between Gears H L H H
Between Gears L L H H
-20 (4HI) L L H L
Between Gears L L H H
Between Gears L H H H
SELECTOR SWITCH
DESCRIPTION
The selector switch assembly is mounted in the left
side of the vehicle's Instrument Panel (IP) and con-
sists of a rotary knob connected to a resistive net-
work for the mode and range shift selections. Also
located in this assembly is a recessed, normally open
momentary switch for making shifts into and out of
transfer case NEUTRAL. A pen, or similar instru-
ment, is used to make a NEUTRAL shift selection,
thus reducing the likelihood of an inadvertent shift
request.The selector switch also contains light emitting
diode's (LED's) to indicate the transfer case position
and whether a shift is in progress.
DRTRANSFER CASE - NV244 GENII 21 - 539
MODE SENSOR (Continued)

SHIFT MOTOR
DESCRIPTION
The shift motor (Fig. 85) consists of a permanent
magnet D.C. motor with gear reduction to convert a
high speed-low torque device into a low speed-high
torque device. The output of the device is coupled to
a shaft which internally moves the mode and range
forks that change the transfer case operating ranges.
The motor is rated at 25 amps maximum at 72É F
with 10 volts at the motor leads.
OPERATION
The transfer case shift motor responds to the
Transfer Case Control Module (TCCM) commands to
move the transfer case shift sector bi-directionally, as
required, to obtain the transfer case operating mode
indicated by the instrument panel mounted selector
switch.
REMOVAL
NOTE: New shift motor assemblies are shipped in
the 2WD/AWD position. If a new shift motor assem-
bly will be installed, it will be necessary to shift the
transfer case to the 2WD/AWD position prior to
motor removal.
(1) Raise the vehicle on a suitable hoist.
(2) Disengage the wiring connectors from the shift
motor and mode sensor.
(3) Remove the bolts holding the shift motor and
mode sensor assembly onto the transfer case.
(4) Separate the shift motor and mode sensor
assembly from the transfer case.
INSTALLATION
(1) Verify that the shift sector o-ring is clean and
properly positioned over the shift sector and against
the transfer case.
NOTE: Verify that the shift motor position and sec-
tor shaft orientation are aligned. It may be neces-
sary to manually shift the transfer case if the shift
motor and sector shaft are not aligned.
(2) Position the shift motor and mode sensor
assembly onto the transfer case.
(3) Install the bolts to hold the assembly onto the
transfer case. Tighten the bolts to 16-24 N´m (12-18
ft.lbs.).
CAUTION: If the original shift motor and mode sen-
sor assembly bolts are reused, be sure to use
MoparTLock & Seal or LoctiteŸ 242 to replenish
the lock patch material originally found on the bolts
(4) Engage the wiring connectors to the shift motor
and mode sensor.
(5) Refill the transfer case as necessary.
(6) Lower vehicle and verify transfer case opera-
tion.
Fig. 85 Shift Motor - Shown Inverted - Typical
1 - SHIFT MOTOR
DRTRANSFER CASE - NV244 GENII 21 - 541

TRANSFER CASE - NV273
TABLE OF CONTENTS
page page
TRANSFER CASE - NV273
DESCRIPTION........................542
OPERATION..........................543
DIAGNOSIS AND TESTING - TRANSFER
CASE - NV273.......................543
REMOVAL............................544
DISASSEMBLY........................544
CLEANING...........................554
INSPECTION.........................554
ASSEMBLY...........................556
INSTALLATION........................568
SPECIFICATIONS
TRANSFER CASE - NV273.............568
SPECIAL TOOLS
TRANSFER CASE NV271/NV273.........569
EXTENSION HOUSING SEAL AND DUST BOOT
REMOVAL............................571
INSTALLATION........................571FLUID
STANDARD PROCEDURE - FLUID DRAIN AND
REFILL............................571
FRONT OUTPUT SHAFT SEAL
REMOVAL............................572
INSTALLATION........................572
MODE SENSOR
DESCRIPTION........................573
OPERATION..........................573
SELECTOR SWITCH
DESCRIPTION........................574
OPERATION..........................574
SHIFT MOTOR
DESCRIPTION........................575
OPERATION..........................575
REMOVAL............................575
INSTALLATION........................575
TRANSFER CASE - NV273
DESCRIPTION
The NV273 is an electronically controlled part-time
transfer case with a low range gear reduction system.
The NV273 has three operating ranges plus a NEU-
TRAL position. The low range system provides a gear
reduction ratio for increased low speed torque capa-
bility.
The geartrain is mounted in two aluminum case
halves attached with bolts. The mainshaft front and
rear bearings are mounted in aluminum case halves.
OPERATING RANGES
Transfer case operating ranges are:
²2WD (2-wheel drive)
²4HI (4-wheel drive)
²4LO (4-wheel drive low range)
²NEUTRAL
The 2WD range is for use on any road surface at
any time.The 4HI and 4LO ranges are for off road use only.
They are not for use on hard surface roads. The only
exception being when the road surface is wet or slip-
pery or covered by ice and snow.
The low range reduction gear system is operative
in 4LO range only. This range is for extra pulling
power in off road situations. Low range reduction
ratio is 2.72:1.
SHIFT MECHANISM
Operating ranges are selected with a dash
mounted shift selector switch. The shift selector
switch provides a input to the Transfer Case Control
Module (TCCM) to indicate the driver's desire to
change operating ranges. The TCCM uses this input,
along with input from the transfer case mounted
mode sensor and information from the vehicle's bus,
to determine if a shift is permitted. If the TCCM
decides the shift is permitted, the TCCM controls the
shift motor, mounted to the exterior of the transfer
case, to perform the shift.
21 - 542 TRANSFER CASE - NV273DR

(7) Install the front companion flange onto the
front output shaft.
(8) Install two bolts 180É apart into the front out-
put shaft companion flange.
(9) Place holder over the bolts and against the
companion flange (Fig. 88).
(10) Install a new front companion flange nut.
Tighten the companion flange nut to 176-271 N´m
(130-200 ft.lbs.).
INSTALLATION
(1) Mount transfer case on a transmission jack.
(2) Secure transfer case to jack with chains.
(3) Position transfer case under vehicle.
(4) Align transfer case and transmission shafts
and install transfer case onto the transmission.
(5) Install and tighten transfer case attaching nuts
to 27-34 N´m (20-25 ft. lbs.) torque.
(6) Connect the vent hose.
(7) Connect the shift motor and mode sensor wir-
ing connectors. Secure wire harness to clips on trans-
fer case.
(8) Align and connect the propeller shafts.
(9) Fill transfer case with correct fluid. (Refer to
21 - TRANSMISSION/TRANSFER CASE/FLUID -
STANDARD PROCEDURE)
(10) Install skid plate, if equipped.(11) Remove transmission jack and support stand.
(12) Lower vehicle and verify transfer case shift
operation.
SPECIFICATIONS
TRANSFER CASE - NV273
TORQUE SPECIFICATIONS
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Plug, Detent 16-24 12-18 -
Plug, Drain/Fill 20-34 15-25 -
Bolt, Extension Housing 27-34 20-25 -
Bolt, Case Half 27-34 20-25 -
Support, Sector 27-34 20-25 -
Nuts, Mounting 30-41 20-30 -
Bolts, Shift Motor and
Mode Sensor Assembly16-25 12-18 -
Nut, Companion Flange 176-271 130-200 -
Fig. 88 Install Companion Flange Nut
1 - HOLDER 6719
2 - BOLTS
21 - 568 TRANSFER CASE - NV273DR
TRANSFER CASE - NV273 (Continued)

have not been met. This is in an attempt to notify
the driver that the transmission needs to be put into
NEUTRAL, the vehicle speed is too great, or some
other condition outlined (other than a diagnostic fail-
ure that would prevent this shift) elsewhere (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/TRANSFER CASE CONTROL MODULE -
OPERATION) is not met. Note that this flashing will
continue indefinitely until the conditions are eventu-
ally met, or the selector switch position is changed,
or if diagnostic routines no longer allow the
requested shift.
²
If the driver attempts to make a shift into transfer
case NEUTRAL, and any of the driver controllable con-
ditions are not met, the request will be ignored until all
of the conditions are met or until the NEUTRAL select
button is released. Additionally the neutral lamp will
flash, or begin to flash while the button is depressed
and operator controllable conditions are not being met.
All of the LED's except the Neutral will flash if any of
the operator controllable conditions for shifting are not
met while the Neutral button is depressed. This9toggle9
type of feature is necessary because the TCCM would
interpret another request immediately after the shift
into transfer case NEUTRAL has completed.
²No LED's illuminated indicate a fault in the
transfer case control system.
SHIFT MOTOR
DESCRIPTION
The shift motor (Fig. 96) consists of a permanent
magnet D.C. motor with gear reduction to convert a
high speed-low torque device into a low speed-high
torque device. The output of the device is coupled to
a shaft which internally moves the mode and range
forks that change the transfer case operating ranges.
The motor is rated at 25 amps maximum at 72É F
with 10 volts at the motor leads.
OPERATION
The transfer case shift motor responds to the
Transfer Case Control Module (TCCM) commands to
move the transfer case shift sector bi-directionally, as
required, to obtain the transfer case operating mode
indicated by the instrument panel mounted selector
switch.
REMOVAL
NOTE: New shift motor assemblies are shipped in
the 2WD/AWD position. If a new shift motor assem-
bly will be installed, it will be necessary to shift the
transfer case to the 2WD/AWD position prior to
motor removal.(1) Raise the vehicle on a suitable hoist.
(2) Disengage the wiring connectors from the shift
motor and mode sensor.
(3) Remove the bolts holding the shift motor and
mode sensor assembly onto the transfer case.
(4) Separate the shift motor and mode sensor
assembly from the transfer case.
INSTALLATION
(1) Verify that the shift sector o-ring is clean and
properly positioned over the shift sector and against
the transfer case.
NOTE: Verify that the shift motor position and sec-
tor shaft orientation are aligned. It may be neces-
sary to manually shift the transfer case if the shift
motor and sector shaft are not aligned.
(2) Position the shift motor and mode sensor
assembly onto the transfer case.
(3) Install the bolts to hold the assembly onto the
transfer case. Tighten the bolts to 16-24 N´m (12-18
ft.lbs.).
CAUTION: If the original shift motor and mode sen-
sor assembly bolts are reused, be sure to use
MoparTLock & Seal or LoctiteŸ 242 to replenish
the lock patch material originally found on the bolts
(4) Engage the wiring connectors to the shift motor
and mode sensor.
(5) Refill the transfer case as necessary.
(6) Lower vehicle and verify transfer case
operation.
Fig. 96 Shift Motor - Shown Inverted - Typical
1 - SHIFT MOTOR
DRTRANSFER CASE - NV273 21 - 575
SELECTOR SWITCH (Continued)

ROAD TESTING WIND NOISE
(1) Drive the vehicle to verify the general location
of the wind noise.
(2) Apply 50 mm (2 in.) masking tape in 150 mm
(6 in.) lengths along weatherstrips, weld seams or
moldings. After each length is applied, drive the vehi-
cle. If noise goes away after a piece of tape is applied,
remove tape, locate, and repair defect.
POSSIBLE CAUSE OF WIND NOISE
²Moldings standing away from body surface can
catch wind and whistle.
²Gaps in sealed areas behind overhanging body
flanges can cause wind-rushing sounds.
²Misaligned movable components.
²Missing or improperly installed plugs in pillars.
²Weld burn through holes.
STANDARD PROCEDURE
STANDARD PROCEDURE - BODY LUBRICATION
All mechanisms and linkages should be lubricated
when necessary. This will maintain ease of operation
and provide protection against rust and excessive
wear. The weatherstrip seals should be lubricated to
prolong their life as well as to improve door sealing.
All applicable exterior and interior vehicle operat-
ing mechanisms should be inspected and cleaned.
Pivot/sliding contact areas on the mechanisms should
then be lubricated.
(1) When necessary, lubricate the operating mech-
anisms with the specified lubricants.
(2) Apply silicone lubricant to a cloth and wipe it
on door seals to avoid over-spray that can soil pas-
senger's clothing.
(3) Before applying lubricant, the component
should be wiped clean. After lubrication, any excess
lubricant should be removed.
(4) The hood latch, latch release mechanism, latch
striker, and safety latch should be lubricated period-
ically.
(5) The door lock cylinders should be lubricated
twice each year (preferably autumn and spring).
²Spray a small amount of lock cylinder lubricant
directly into the lock cylinder.
²Apply a small amount to the key and insert it
into the lock cylinder.
²Rotate it to the locked position and then back to
the unlocked position several times.
²Remove the key. Wipe the lubricant from it with
a clean cloth to avoid soiling of clothing.
STANDARD PROCEDURE - HEAT STAKING
(1) Remove trim panel.(2) Bend or move the trim panel components at
the heat staked joints. Observe the heat staked loca-
tions and/or component seams for looseness.
(3) Heat stake the components.
(a) If the heat staked or component seam loca-
tion is loose, hold the two components tightly
together and using a soldering gun with a flat tip,
melt the material securing the components
together. Do not over heat the affected area, dam-
age to the exterior of the trim panel may occur.
(b) If the heat staked material is broken or miss-
ing, use a hot glue gun to apply new material to
the area to be repaired. The panels that are being
heat staked must be held together while the apply-
ing the glue. Once the new material is in place, it
may be necessary to use a soldering gun to melt
the newly applied material. Do not over heat the
affected area, damage to the exterior of the trim
panel may occur.
(4) Allow the repaired area to cool and verify the
repair.
(5) Install trim panel.
STANDARD PROCEDURE - PLASTIC BODY
PANEL REPAIR
There are many different types of plastics used in
today's automotive environment. We group plastics in
three different categories: Rigid, Semi-Rigid, and
Flexible. Any of these plastics may require the use of
an adhesion promoter for repair. These types of plas-
tic are used extensively on DaimlerChrysler Motors
vehicles. Always follow repair material manufactur-
er's plastic identification and repair procedures.
Rigid Plastics:
Examples of rigid plastic use: Fascias, Hoods,
Doors, and other Body Panels, which include SMC,
ABS, and Polycarbonates.
Semi-Rigid Plastics:
Examples of semi-rigid plastic use: Interior Panels,
Under Hood Panels, and other Body Trim Panels.
Flexible Plastics:
Examples of flexible plastic use: Fascias, Body
Moldings, and upper and lower Fascia Covers.
Repair Procedure:
The repair procedure for all three categories of
plastics is basically the same. The one difference is
the material used for the repair. The materials must
be specific for each substrate, rigid repair material
for rigid plastic repair, semi-rigid repair material for
semi-rigid plastic repair and flexible repair material
for flexible plastic repair.
DRBODY 23 - 3
BODY (Continued)

(2) Disengage the rear housing cover retaining
tabs and remove the cover. (Fig. 17)
(3) Disengage the lower glass retaining tab to
motor. (Fig. 18)
(4) Slide glass up and remove from motor.
(5) Disconnect the two heated mirror electrical
connectors, if equipped.
Tow Package Mirror
(1) Position the mirror in the out position. (Fig. 19)
(2) Release the retaining clip and separate the
glass.
(3) Disconnect the four heated glass electrical con-
nectors, if equipped. (Fig. 20)
INSTALLATION
Standard Mirror
(1) Connect the two heated mirror electrical con-
nectors, if equipped. (Fig. 21)
(2) Position the mirror glass mounting holes over
the four feet of the mirror motor and slide down.
(Fig. 22)
(3) Engage the lower glass retaining tab to the
motor. (Fig. 18)
(4) Position the rear housing cover and seat the
retaining tabs fully. (Fig. 17)
Tow Package Mirror
(1) Make sure the retaining clip is seated in the
closed position on the mirror glass.
Fig. 16 STANDARD MIRROR POSITION
1 - RETAINING TABS (2)
2 - MIRROR HOUSING
3 - MIRROR GLASS
Fig. 17 STANDARD MIRROR HOUSING COVER
1 - MIRROR HOUSING COVER
2 - RETAINING TABS (3)
Fig. 18 STANDARD MIRROR RETAINING TAB
1 - MIRROR ASSEMBLY
2 - MIRROR GLASS LOWER RETAINING TAB
Fig. 19 TOW PACKAGE MIRROR POSITION
1 - MIRROR HOUSING ASSEMBLY
2 - MIRROR GLASS RETAINING CLIP
3 - MIRROR GLASS
DREXTERIOR 23 - 43
SIDE VIEW MIRROR GLASS (Continued)

(2) Connect the heated mirror electrical connec-
tors, if equipped.
NOTE: Pressure must be applied equally over the
center portion of the mirror to engage the mirror
glass retaining clip fully.
(3) Position the glass over the motor mounting and
seat fully. Make sure the retaining clip seats fully.
REAR FENDER
REMOVAL
(1) Remove the wheel house splash shield. (Refer
to 23 - BODY/EXTERIOR/REAR WHEELHOUSE
SPLASH SHIELD - REMOVAL)
(2) Disconnect the marker lamps electrical connec-
tors.
(3) Remove the tail lamp units. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
TAIL LAMP UNIT - REMOVAL)
(4) Remove the two fender nuts. (Fig. 23)
(5) Remove the rear inner nuts below the tail
lamp. (Fig. 24)
(6) Remove the two bolts at the rear bottom edge.
(7) Remove the two bolts at the front bottom edge.
(8) Remove the four inner nuts front edge. (Fig.
25)
(9) Loosen bolts and loosen the two fender support
brackets. (Fig. 26)
CAUTION: Mask off the surrounding box area to
avoid damage to the painted surfaces.
(10) Lift the fender up off the support brackets
and remove the fender.
INSTALLATION
CAUTION: Mask off the surrounding box area to
avoid damage to the painted surfaces during instal-
lation.
Fig. 20 TOW PACKAGE MIRROR GLASS
1 - HEATED GLASS ELECTRICAL CONNECTORS (IF EQUIPPED)
2 - MIRROR GLASS
3 - RETAINING CLIP
Fig. 21 STANDARD MIRROR INSTALLATION
1 - MIRROR GLASS
2 - UPPER AND LOWER RETAINING CLIPS
3 - HEATED MIRROR ELECTRICAL CONNECTORS (IF
EQUIPPED)
4 - MIRROR GLASS MOUNTING HOLES (4)
Fig. 22 STANDARD MIRROR ASSEMBLY
1 - HEATED MIRROR ELECTRICAL CONNECTORS (IF
EQUIPPED)
2 - MIRROR HOUSING
3 - HOUSING COVER LOCKING TABS
4 - MIRROR GLASS MOUNTING FEET (4)
23 - 44 EXTERIORDR
SIDE VIEW MIRROR GLASS (Continued)

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING
SYSTEM REQUIREMENTS...............1
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
OPERATION - HEATER AND AIR
CONDITIONER........................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................3DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST..................6
SPECIFICATIONS - A/C SYSTEM............7
CONTROLS.............................9
DISTRIBUTION..........................26
PLUMBING.............................41
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 A/C condenser
will reduce the performance of the A/C 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 or a manually controlled dual
zone type heating-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 block²Heater core
²Evaporator coil
²Blend door and actuator
²Defrost 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 outlet is located on
the top of the housing, the panel outlet is located on
the face 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 further directed
through molded plastic ducts to the various 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
each outboard end of the instrument panel top cover,
near the belt line at the A-pillars.
²Panel Outlets- There are four panel outlets in
the instrument panel, one located near each outboard
end of the instrument panel facing the rear of the
vehicle and two 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 floor panel
center tunnel near the dash panel.
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, then into the plenum cham-
DRHEATING & AIR CONDITIONING 24 - 1

ber above the heating, ventilation and air condition-
ing (HVAC) housing. On models equipped with air
conditioning, the air passes through the evaporator
coil. Air flow can be directed either through or
around the heater core. This is done by adjusting the
blend door with the temperature control knob on the
A/C-heater control located the instrument panel. The
air flow can then be directed from the panel, floor
and defrost outlets 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 selector located on the A/C-heater control.
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 systems are blend-
air type systems. In a blend-air system, a blend door
controls the amount of unconditioned air (or cooled
air from the evaporator on models with air condition-
ing) that is allowed to flow through, or around, the
heater core. A temperature control knob determines
the discharge air temperature by actuating an elec-
tric motor, which operates the blend door. This allows
an almost immediate control of the output air tem-
perature of the system.
On all models, the outside air intake can be shut
off by selecting the Recirculation Mode with the
mode control knob. This will operate a electric actu-
ated 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.
The defroster outlet receives airflow from the
HVAC housing through the molded plastic defroster
duct, which connects to the HVAC housing defroster
outlet. The airflow from the defroster outlets is
directed by fixed vanes in the defroster outlet grilles
and cannot be adjusted. The defroster outlet grilles
are integral to the instrument panel top cover.
The side window demister outlets receive airflow
from the HVAC housing through the molded plastic
defroster duct and two molded plastic demister ducts.
The airflow from the side window demister outlets is
directed by fixed vanes in the demister outlet grilles
and cannot be adjusted. The side window demister
outlet grilles are integral to the instrument panel.
The demisters direct air from the HVAC housing
through the outlets located on the top corners of the
instrument panel. The demisters operate when the
mode control knob is positioned in the floor-defrost
and defrost-only settings. Some air may be noticeable
from the demister outlets when the mode control is
in the bi-level to floor positions.
Fig. 1 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 - 2 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)