DODGE RAM 1500 1998 2.G Workshop Manual

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)

(2) Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL CENTER BEZEL - REMOVAL).
(3) Disconnect the wire harness connector from the
recirculation door actuator (Fig. 23).
(4) Remove the screws that secure the recircula-
tion door actuator to the air inlet housing.
(5) Remove the recirculation door actuator from
the air inlet housing.INSTALLATION
(1) Position the recirculation door actuator onto
the air inlet housing. If necessary, rotate the actuator
slightly to align the splines on the actuator output
shaft with those in the recirculation air door.
(2) Install and tighten the screws that secure the
recirculation door actuator to the air inlet housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the HVAC wire harness connector to
the recirculation door actuator.
(4) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(5) Reconnect the battery negative cable.
Fig. 23 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
DRCONTROLS 24 - 25
RECIRCULATION DOOR ACTUATOR (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
AIR OUTLETS
DESCRIPTION.........................26
REMOVAL.............................26
INSTALLATION.........................27
BLEND DOOR
REMOVAL.............................27
INSTALLATION.........................27
BLOWER MOTOR
DESCRIPTION.........................28
OPERATION...........................28
DIAGNOSIS AND TESTING - BLOWER
MOTOR .............................28
REMOVAL.............................31
INSTALLATION.........................31
DEFROST DOOR
REMOVAL.............................31
INSTALLATION.........................31
DEFROSTER DUCT
REMOVAL.............................32
INSTALLATION.........................32FLOOR DISTRIBUTION DUCT
REMOVAL.............................33
INSTALLATION.........................34
HVAC HOUSING
REMOVAL.............................34
DISASSEMBLY.........................35
ASSEMBLY............................35
INSTALLATION.........................36
INSTRUMENT PANEL DEMISTER DUCTS
REMOVAL.............................36
INSTALLATION.........................37
INSTRUMENT PANEL DUCTS
REMOVAL.............................37
INSTALLATION.........................37
MODE DOOR
REMOVAL.............................38
INSTALLATION.........................38
RECIRCULATION DOOR
REMOVAL.............................39
INSTALLATION.........................40
AIR OUTLETS
DESCRIPTION
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 instrument panel cen-
ter bezel. The air outlets can be removed individually
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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
24 - 26 DISTRIBUTIONDR

NOTE: The instrument panel air outlets are retained
into the outlet housings by a light snap fit.
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the panel air outlet(s) out
of the panel outlet housing(s) as required (Fig. 1).
INSTALLATION
(1) Position the air outlet(s) onto the outlet hous-
ing(s).
(2) Gently push the air outlet into the housing
until it snaps into position.
BLEND 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.NOTE: Vehicles equiped with single zone HVAC
systems have one blend door, dual zone systems
have two blend doors.
(1) Remove the HVAC housing from the vehicle
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - DISASSEMBLY).
(3) Remove the levers from the driver and/or pas-
senger side blend door (if equipped) (Fig. 2).
(4) Gently slide the drivers and/or passenger side
blend door toward the out side of the housing. Tilt
and lift the door(s) out of the housing.
(5) Inspect the blend door(s), seals and the HVAC
housing for damage or binding and repair or replace
components as required.
INSTALLATION
(1) Position the blend door pivot shafts into the
pivot hole and actuator in the bottom of the lower
half of the HVAC housing.
(2) Install the blend door(s) by carefully tipping
the doors into the HVAC housing, then sliding each
door into it's operating position.
(3) Install the levers to the driver and/or passen-
ger side blend door (if equipped).
(4) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY)
Fig. 1 Instrument Panel Air Outlets
1 - HEADLIGHT SWITCH
2 - AIR OUTLETS
3 - INSTRUMENT CLUSTER
4 - CLIMATE CONTROL
5 - RADIO
6 - AIRBAG
7 - GLOVE BOX
8 - HEATED SEAT SWITCH (IF EQUIPPED)
9 - TRANSFER CASE SWITCH (IF EQUIPPED)
10 - CIGAR LIGHTER
11 - CUP HOLDERS
12 - ASH TRAY (IF EQUIPPED)
13 - POWER OUTLET
Fig. 2 Blend Door - Dual Zone Shown, Single Zone
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
DRDISTRIBUTION 24 - 27
AIR OUTLETS (Continued)

(5) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION)
BLOWER MOTOR
DESCRIPTION
The blower motor and blower wheel are located in
the passenger side end of the HVAC housing, below
the glove box. The blower motor controls the velocity
of air flowing through the HVAC housing by spinning
a squirrel cage-type blower wheel within the housing
at the selected speed. The blower motor and wheel
can be removed from the housing inside the vehicle
without removing the instrument panel or HVAC
housing.
OPERATION
The blower motor will only operate with the igni-
tion switch in the On position and the A/C-heater
mode control switch in any position, except Off. The
blower motor receives a fused battery feed circuit
through a fuse in the Power Distribution Center
(PDC) whenever the ignition switch is in the On posi-
tion. Blower motor speed is controlled by regulating
the ground path through or around the blower motor
resistor block and through the A/C-heater blower
motor switch.
The blower motor and blower motor wheel are ser-
viced only as a unit and cannot be repaired and, if
faulty or damaged, must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
BLOWER MOTOR INOPERATIVE
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.
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.
BLOWER MOTOR ELECTRICAL DIAGNOSIS
Refer to the Blower Motor Electrical Diagnosis
chart for basic checks of the blower motor circuit
(Fig. 3).
BLOWER MOTOR NOISE OR VIBRATION
Refer to the Blower Motor Noise/Vibration Diagno-
sis chart for basic checks of the blower motor when a
vibration or noise is present (Fig. 4).
24 - 28 DISTRIBUTIONDR
BLEND DOOR (Continued)

Fig. 3 Blower Motor Electrical Diagnosis
DRDISTRIBUTION 24 - 29
BLOWER MOTOR (Continued)

Fig. 4 Blower Motor Noise/Vibration Diagnosis
24 - 30 DISTRIBUTIONDR
BLOWER MOTOR (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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
NOTE: The blower motor is located on the passen-
ger side of the vehicle under the instrument panel.
The blower motor can be removed from the vehicle
without having to remove the HVAC housing.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connector from the
blower motor. (Fig. 5).
(3) Remove the three screws that secure the
blower motor to the HVAC housing.
(4) Remove the blower motor from the HVAC hous-
ing by rotating and tilting the blower motor as
needed for clearance.
INSTALLATION
(1) Align and install the blower motor into the
HVAC housing.
(2) Install the three screws that secure the blower
motor to the HVAC housing. Tighten the screws to
2.2 N´m (20 in. lbs.).
(3) Connect the wire harness connector to the
blower motor.
(4) Reconnect the battery negative cable.
DEFROST 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. THISIS 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) Disassemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - DISASSEMBLY).
(3) Remove the defrost door actuator and sleeve
from the lower half of the HVAC housing (Fig. 6).
(4) Gently slide the defrost door toward the out-
side of the housing. Tilt and lift the door out of the
housing.
(5) Inspect the defrost door, seals and the HVAC
housing for damage or binding and repair or replace
components as required.
INSTALLATION
(1) Position the defrost door pivot shaft into the
pivot hole in the lower half of the HVAC housing.
(2) Install the defrost door actuator and sleeve.
(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)
Fig. 5 HVAC Blower Motor - Typical
1 - RESISTOR BLOCK SCREWS (2)
2 - BLOWER MOTOR RESISTOR BLOCK
3 - RESISTOR BLOCK WIRE CONNECTOR
4 - BLOWER MOTOR SCREW
5 - BLOWER MOTOR
6 - BLOWER MOTOR WIRE CONNECTOR
7 - BLOWER MOTOR SCREW
8 - HVAC HOUSING
9 - WIRE HARNESS RETAINER (2)
10 - BLOWER MOTOR SCREW
DRDISTRIBUTION 24 - 31
BLOWER MOTOR (Continued)

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)