2003 DODGE RAM Hvac actuator

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Door Ajar Switch-Driver (Base) BK Left Front Door 42
Door Ajar Switch-Left Rear (Base) BK Left Rear Door 43
Door Ajar Switch-Passenger (Base) BK Right Front Door N/S
Door Ajar Switch-Right Rear (Base) BK Right Rear Door 43
Door Lock Motor/Ajar Switch-Driver
(Except Base)BK Left Front Door 42
Door Lock Motor/Ajar Switch-Left
Rear (Except Base)BK Left Rear Door 43
Door Lock Motor/Ajar Switch-
Passenger (Except Base)BK Right Front Door N/S
Door Lock Motor/Ajar Switch-Right
Rear (Except Base)BK Right Rear Door 43
Door Lock Switch-Passenger BL In Right Front Door N/S
Driver Airbag Squib BK In Steering Column N/S
Driver Blend Door Actuator (Dual
Zone)BK Right Side of HVAC N/S
Driver Door Module C1 BL In Left Front Door 42
Driver Door Module C2 BL In Left Front Door 42
Engine Control Module C1 BK Left Engine 10
Engine Control Module C2 BK Left Engine 10
Engine Coolant Temperature
SensorBK Near Generator 4, 7, 9
Engine Oil Pressure Sensor BK Lower Left Side of Engine 4, 6, 8, 9, 11
Evap/Purge Solenoid BK Left Fender Side Shield 26, 28
Evaporator Temperature Sensor BK Right Side of HVAC N/S
Fog Lamp-Left WT Left Front Facia N/S
Fog Lamp-Right WT Right Front Facia N/S
Fuel Control Actuator (Diesel) BK Left Rear Engine 23
Fuel Heater (Diesel) BK Left Side Engine 10
Fuel Injector No.1 BK At Fuel Injector 4, 8
Fuel Injector No. 2 BK At Fuel Injector 3, 7
Fuel Injector No. 3 BK At Fuel Injector 4, 8
Fuel Injector No. 4 BK At Fuel Injector 3, 7
Fuel Injector No. 5 BK At Fuel Injector 4, 8
Fuel Injector No. 6 BK At Fuel Injector 3, 7
Fuel Injector No. 7 BK At Fuel Injector 4, 8
Fuel Injector No. 8 BK At Fuel Injector 3, 7
Fuel Pump Module LT GY At Fuel Tank 48
Fuel Pump Motor (Diesel) BK Left Side Engine 10
Generator BK Front of Engine 4, 6, 7, 10
Glove Box Lamp and Switch BK At Glove Box 37, 40
Governor Pressure Sensor BK Left Rear of Transmission N/S
Headlamp Switch BK Left Side of Instrument Panel 34, 37, 39
Headlamp-Left BL At Headlamp 26, 30, 31
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Manifold Absolute Pressure Sensor
(5.9L)BK Left Front of Intake Manifold 8
Mode Door Actuator 1 BK Right Side of HVAC N/S
Mode Door Actuator 2 BK Right Side of HVAC N/S
Multi-Function Switch BK On Steering Column N/S
Natural Vacuum Leak Detection
AssemblyBK Rear of Transmission 18, 19
Output Speed Sensor DB Left Side of Transmission 11, 12, 14, 15
Overdrive Switch WT Center of Instrument Panel 37
Overhead Map/Reading Lamp
(Except Base)NAT Center of Headliner N/S
Oxygen Sensor 1/1 Upstream BK Left Front of Side of Transmission 11, 12, 14, 16
Oxygen Sensor 1/2 Downstream NAT Left Rear of Side of Transmission 11, 14, 16
Oxygen Sensor 2/1 Upstream BK Right Front Side of Transmission 11, 12, 14, 16, 17, 18,
19
Oxygen Sensor 2/2 Downstream BK Right Rear Side of Transmission 11, 12, 14, 16, 17, 18,
19
Park Brake Switch At Park Brake 26, 27
Park/Turn Signal Lamp-Left Front BK At Lamp 26, 30, 31
Park/Turn Signal Lamp-Right Front BK At Lamp 1, 25, 29
Passenger Airbag On/Off Switch Right Side of Instrument Panel 35, 37, 40
Passenger Blend Door Actuator
(Dual Zone)BK Right Side of HVAC N/S
Passenger Lumbar Switch At Passenger Seat N/S
Power Mirror-Left BK At Mirror 42
Power Mirror-Right BK At Mirror N/S
Power Outlet RD Center of Instrument Panel 37
Power Outlet-Console BK Center of Instrument Panel N/S
Power Seat Motor-Driver Front
VerticalRD At Driver Seat N/S
Power Seat Motor-Driver Horizontal BK At Driver Seat N/S
Power Seat Motor-Driver Rear
VerticalBK At Driver Seat N/S
Power Seat Switch-Driver BK At Driver Seat N/S
Power Seat Switch-Passenger BK At Passenger Seat N/S
Power Steering Pressure Switch BK Near Power Steering Pump 4, 5
Power Window Circuit Breaker Under Instrument Panel 33, 37, 39
Power Window Motor-Driver BK In Driver Door at Motor 42
Power Window Motor-Left Rear BK In Door at Motor 43
Power Window Motor-Passenger BK In Passenger Door at Motor N/S
Power Window Motor-Right Rear BK In Door at Motor 43
Power Window Switch-Left Rear BL In Door 43
Power Window Switch-Right Rear BL In Door 43
Powertrain Control Module C1 BK Right Rear Engine Compartment 21, 22, 23, 24
8W - 91 - 6 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Powertrain Control Module C2 WT Right Rear Engine Compartment 21, 22, 23, 24
Powertrain Control Module C3 GY Right Rear Engine Compartment 21, 22, 23, 24
Powertrain Control Module C4 GN Right Rear Engine Compartment 21
PTO Sense Near G107 21, 22, 24
Radio (Base) GY Rear of Radio 37, 38
Radio (Premium) BK Rear of Radio 37, 38
Recirculation Door Actuator BK Right Side of HVAC N/S
Red Brake Warning Indicator
SwitchBK Near Master Cylinder 26, 28, 31
Remote Radio Switch-Left BK At Steering Wheel N/S
Remote Radio Switch-Right BK At Steering Wheel N/S
Seat Belt Pretensioner-Left YL Left B-Pillar 44, 45
Seat Belt Pretensioner-Right YL Right B-Pillar N/S
Seat Belt Switch-Driver DK GY Left B-Pillar N/S
Seat Belt Tension Reducer
(Standard Cab)YL Left B-Pillar 44
Seat Heater Interface Module GN Under Driver Seat N/S
Sentry Key Immobilizer Module BK On Steering Column 32
Side Marker - Left Front (Dual
Wheels)BK Front of Left Rear Fender 50
Side Marker - Left Rear (Dual
Wheels)BK Rear of Left Rear Fender 50
Side Marker - Right Front (Dual
Wheels)BK Front of Right Rear Fender 50
Side Marker - Right Rear (Dual
Wheels)BK Rear of Right Rear Fender 50
Speaker-Center Instrument Panel WT Center of Instrument Panel 37, 38
Speaker-Left Front Door WT In Left Front Door 42
Speaker-Left Instrument Panel BK Left Side of Instrument Panel 37, 39
Speaker-Left Rear (Standard Cab) WT In Lower Left B-Pillar 44
Speaker-Left Rear Door (Quad
Cab)WT In Left Rear Door 43
Speaker-Right Front Door WT In Right Front Door N/S
Speaker-Right Instrument Panel BK Right Side of Instrument Panel 37, 40
Speaker-Right Rear (Standard
Cab)BK In Lower Right B-Pillar N/S
Speaker-Right Rear Door (Quad
Cab)BK In Right Rear Door 43
Speed Control Servo BK Left Front Side of Engine
Compartment26, 28
Speed Control Switch - Left
(Except ETC)GN Steering Wheel N/S
Speed Control Switch - Right
(Except ETC)GN Steering Wheel N/S
Speed Control Switch-Left (ETC) WT At Steering Wheel N/S
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 7
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS.......................1
DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT........................1
OPERATION
OPERATION - HEATER AND AIR
CONDITIONER........................1
OPERATION - REFRIGERANT SYSTEM
SERVICE PORT........................2DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................2
DIAGNOSIS AND TESTING - HEATER
PERFORMANCE.......................5
STANDARD PROCEDURE - DIODE
REPLACEMENT.......................7
SPECIFICATIONS
A/C APPLICATION TABLE................7
SPECIFICATIONS......................8
CONTROLS.............................9
DISTRIBUTION..........................24
PLUMBING.............................31
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR
CONDITIONER
All vehicles are equipped with a common HVAC
housing assembly (Fig. 1). The system combines air
conditioning, heating, and ventilating capabilities in
a single unit housing mounted under the instrument
panel.
DESCRIPTION - COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the HVAC
system, the engine cooling system must be properly
maintained. The use of a bug screen is not recom-
mended. Any obstructions in front of the radiator or
condenser will reduce the performance of the air con-
ditioning and engine cooling systems.
The engine cooling system includes the heater core
and the heater hoses. Refer to Engine Cooling for
more information before the opening of, or attempt-
ing any service to the engine cooling system.
DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT
The two refrigerant system service ports are used
to charge, recover/recycle, evacuate, and test the air
conditioning refrigerant system. Unique service port
coupler sizes are used on the R-134a system, toensure that the refrigerant system is not accidentally
contaminated by the use of the wrong refrigerant
(R-12), or refrigerant system service equipment.
OPERATION
OPERATION - HEATER AND AIR CONDITIONER
The heater air conditioner are blend-air type sys-
tems. In a blend-air system, a blend door controls the
amount of unconditioned air (or cooled air from the
evaporator on models with air conditioning) that is
allowed to flow through, or around, the heater core. A
temperature control knob on the A/C Heater control
panel determines the discharge air temperature by
controlling an electric actuator, which moves the
blend door. This allows an almost immediate control
of the output air temperature of the system.
The mode control knob on the A/C Heater control
panel is used to direct the conditioned air to the
selected system outlets. Both mode control switches
use electric actuators to control the mode doors.
On all vehicles, 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 door that closes off the outside
fresh air intake and recirculates the air that is
already inside the vehicle.
The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a fixed
orifice tube in the liquid line near the condenser out-
let tube to meter refrigerant flow to the evaporator
DRHEATING & AIR CONDITIONING 24 - 1

coil. To maintain minimum evaporator temperature
and prevent evaporator freezing, the A/C Fin Probe
which is located in the evaporator cycles the com-
pressor clutch by sending an A/C request to the
JTEC which in turn processes this piece of informa-
tion and if all conditions are met cycles the compres-
sor clutch.
OPERATION - REFRIGERANT SYSTEM SERVICE
PORT
The low pressure service port is located on the suc-
tion refrigerant line, near the accumulator. The high
pressure service port is located on the liquid line at
the passenger side of the engine compartment, near
the condenser.
Each of the service ports has a threaded plastic
protective cap installed over it from the factory. After
servicing the refrigerant system, always reinstall
both of the service port caps.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to provide
the passenger compartment with low temperature
and low humidity air. The evaporator, located in the
HVAC housing on the dash panel below the instru-
ment panel, is cooled to temperatures near the freez-
ing point. As warm damp air passes through the
cooled evaporator, the air transfers its heat to the
refrigerant in the evaporator and the moisture in the
air condenses on the evaporator fins. During periods
of high heat and humidity, an air conditioning sys-
tem will be more effective in the Recirculation Mode.
With the system in the Recirculation Mode, only air
from the passenger compartment passes through the
evaporator. As the passenger compartment air dehu-
midifies, the air conditioning system performance
levels improve.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the air condition-
ing system. When humidity is high, the evaporator
has to perform a double duty. It must lower the air
temperature, and it must lower the temperature of
the moisture in the air that condenses on the evapo-
rator fins. Condensing the moisture in the air trans-
fers heat energy into the evaporator fins and tubing.
This reduces the amount of heat the evaporator can
absorb from the air. High humidity greatly reduces
the ability of the evaporator to lower the temperature
of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Remov-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from the
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
Before proceeding, (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION). The air temperature in
the test room and in the vehicle must be a minimum
of 21É C (70É F) for this test.
(1) Connect a tachometer and a manifold gauge set
or A/C recycling/charging station.
(2) Set the A/C Heater mode control switch knob in
the Recirculation Mode position, the temperature
control knob in the full cool position, and the blower
motor switch knob in the highest speed position.
Fig. 1 HVAC Housing - Dual Zone Shown (Typical -
Single Zone)
1 - Mounting Nut
2 - Passenger Blend Door Actuator (dual zone)
3 - Mounting Nut
4 - Air Intake Spacer
5 - Recirculation Door Actuator
6 - Recirculation Door Assembly
7 - Driver Side Blend Door Actuator
8 - HVAC Housing
9 - Mounting Screw
10 - Defroster Door Actuator
11 - Panel Actuator
24 - 2 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)

SPECIFICATIONS
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
A/C COMPRESSOR
CLUTCH PLATE NUT14.4 10.5 127.4
A/C COMPRESOR LINE
MANIFOLD FASTENER28 ( 6) 21 ( 4) 250 ( 50)
A/C COMPRESSOR TO
MOUNTING BRACKET
BOLTS27 20 239
ACCUMULATOR
RETAINING BOLT5 3.7 44
BLEND DOOR ACTUATOR
SCREWS2.4 ( .34) 1.8 ( .25) 21 ( 3)
HVAC HOUSING SCREWS 2.4 ( .34) 1.8 ( .25) 21 ( 3)
HVAC HOUSING TO DASH
PANEL NUTS6.2 4.6 55
SUCTION LINE TO
ACCUMULATOR FITTING9 6.6 80
24 - 8 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)

an A/C pressure transducer voltage reading between
0.451 and 4.519 volts is required. Voltages outside
this range indicate a low or high refrigerant system
pressure condition to the Powertrain Control Module
(PCM). The PCM is programmed to respond to a low
or high refrigerant system pressure by suppressing
operation of the compressor. Refer to the A/C Pres-
sure Transducer Voltage table for the possible condi-
tion indicated by the transducer voltage readings.
A/C PRESSURE TRANSDUCER VOLTAGE
VOLTAGE POSSIBLE INDICATION
0.0 1. NO SENSOR SUPPLY
VOLTAGE FROM PCM.
2. SHORTED SENSOR CIRCUIT.
3. FAULTY TRANSDUCER.
0.150 TO 0.450 1. AMBIENT TEMPERATURE
BELOW 10É C (50É F).
2. LOW REFRIGERANT
SYSTEM PRESSURE.
0.451 TO 4.519 1. NORMAL REFRIGERANT
SYSTEM PRESSURE.
4.520 TO 4.850 1. HIGH REFRIGERANT
SYSTEM PRESSURE.
5.0 1. OPEN SENSOR CIRCUIT.
2. FAULTY TRANSDUCER.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connector for the
A/C pressure transducer from the transducer connec-
tor receptacle.
(3) Using an open end wrench, unscrew the A/C
pressure transducer from the fitting on the discharge
line between the compressor and the condenser.
(4) Remove the seal from the A/C pressure trans-
ducer fitting and discard.
INSTALLATION
(1) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the A/C pressure
transducer fitting.
(2) Using an open end wrench, install and tighten
the A/C pressure transducer onto the fitting on the
discharge line between the compressor and the con-
denser.
(3) Reconnect the wire harness connector for the
A/C pressure transducer to the transducer connector
receptacle.
(4) Reconnect the battery negative cable.
BLEND DOOR ACTUATOR
DESCRIPTION
The blend door actuators are reversible, 12-volt
Direct Current (DC), servo motors. Models with the
single zone heater and air conditioner system have a
single blend air door, which is controlled by a single
blend door actuator. Models with the optional dual
zone front heater and air conditioner system have
dual blend air doors, which are controlled by two
blend door actuators. The single zone blend door
actuator is located on the driver side end of the heat-
er-A/C housing unit, close to the dash panel. In the
dual zone system, the same blend door actuator used
for the single zone system becomes the driver side
blend door actuator, and is mechanically connected to
only the driver side blend air door. In the dual zone
system, a second separate blend door actuator is also
located on the top of the heater-A/C housing unit and
is mechanically connected to only the passenger side
blend air door.
The blend door actuators are interchangeable with
each other, as well as with the actuators for the
mode door and the recirculation air door. Each actua-
tor is contained within an identical black molded
plastic housing with an integral wire connector
receptacle. Two integral mounting tabs allow the
actuator to be secured with two screws to the heater-
A/C unit housing. Each actuator also has an identical
output shaft with splines that connects it to the link-
age that drives the proper blend air door. The blend
door actuators do not require mechanical indexing to
the blend door linkage, as they are electronically cal-
ibrated by the heater-A/C control module. The blend
door actuators cannot be adjusted or repaired and, if
damaged or faulty, they must be replaced.
OPERATION
Each blend door actuator is connected to the heat-
er-A/C control module through the vehicle electrical
system by a dedicated two-wire take out and connec-
tor of the HVAC wire harness. The blend door actua-
tor can move the blend air door in two directions.
When the heater-A/C control module pulls the volt-
age on one side of the motor connection high and the
other connection low, the blend air door will move in
one direction. When the module reverses the polarity
of the voltage to the motor, the blend air door moves
in the opposite direction. When the module makes
the voltage to both connections high or both connec-
tions low, the blend air door stops and will not move.
These same motor connections also provide a feed-
back signal to the heater-A/C control module. This
feedback signal allows the module to monitor the
operation and relative positions of the blend door
actuator and the blend air door. The heater-A/C con-
24 - 16 CONTROLSDR
A/C PRESSURE TRANSDUCER (Continued)

trol module learns the blend air door stop positions
during the calibration procedure and will store a
Diagnostic Trouble Code (DTC) for any problems it
detects in the blend door actuator circuits. The blend
door actuator can be diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
REMOVAL
The single zone heating and air conditioning sys-
tem is equipped with a single blend door actuator.
The dual zone system has two blend door actuators,
one for the driver side blend air door and one for the
passenger side blend air door. The same service pro-
cedures can be used for each of these actuators.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel assembly(Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL).
(3) Disconnect the HVAC wire harness connector
for the blend door actuator from the actuator connec-
tor receptacle. (Fig. 14)
(4) Remove the screws that secure the blend door
actuator to the distribution housing.
(5) Remove the blend door actuator from the dis-
tribution housing.
INSTALLATION
(1) Position the blend door actuator into the heat-
er/air conditioner housing. If necessary, rotate the
actuator slightly to align the splines on the actuator
output shaft with those in the blend air door linkage.
(2) Install and tighten the three screws that secure
the blend door actuator to the distribution housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector
for the blend door actuator to the actuator connector
receptacle.
(4) Install the instrument panel assembly(Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).(5) Reconnect the battery negative cable.
(6) Perform the heater-A/C control calibration pro-
cedure. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/A/C-HEATER CONTROL
- STANDARD PROCEDURE - HEATER-A/C CON-
TROL CALIBRATION).BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
The blower motor resistor is mounted to the rear
side of the HVAC housing on the passenger side of
the vehicle.
OPERATION
The resistor is a ceramic resistor that utilizes
resistor circuit tracers to reduce current flow to the
Fig. 14 HVAC Housing - Dual Zone Shown (Typical -
Single Zone)
1 - Mounting Nut
2 - Passenger Blend Door Actuator (dual zone)
3 - Mounting Nut
4 - Air Intake Spacer
5 - Recirculation Door Actuator
6 - Recirculation Door Assembly
7 - Driver Side Blend Door Actuator
8 - HVAC Housing
9 - Mounting Screw
10 - Defroster Door Actuator
11 - Panel Actuator
DRCONTROLS 24 - 17
BLEND DOOR ACTUATOR (Continued)