climate control DODGE RAM 2003 Service Repair Manual

DESCRIPTION - CIRCUIT FUNCTIONS
All circuits in the diagrams use an alpha/numeric
code to identify the wire and it's function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second-
ary codes that may apply to some models.
CIRCUIT IDENTIFICATION CODE CHART
CIRCUIT FUNCTION
A BATTERY FEED
B BRAKE CONTROLS
C CLIMATE CONTROLS
D DIAGNOSTIC CIRCUITS
E DIMMING ILLUMINATION
CIRCUITS
F FUSED CIRCUITS
G MONITORING CIRCUITS
(GAUGES)
H OPEN
I NOT USED
J OPEN
K POWERTRAIN CONTROL
MODULE
L EXTERIOR LIGHTING
M INTERIOR LIGHTING
N NOT USED
O NOT USED
P POWER OPTION (BATTERY
FEED)
Q POWER OPTIONS (IGNITION
FEED)
R PASSIVE RESTRAINT
S SUSPENSION/STEERING
T TRANSMISSION/TRANSAXLE/
TRANSFER CASE
U OPEN
V SPEED CONTROL, WIPER/
WASHER
W OPEN
X AUDIO SYSTEMS
Y OPEN
Z GROUNDS
DESCRIPTION - SECTION IDENTIFICATION AND
INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections the
splices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru
8W-09General information and Diagram
Overview
8W-10 thru
8W-19Main Sources of Power and
Vehicle Grounding
8W-20 thru
8W-29Starting and Charging
8W-30 thru
8W-39Powertrain/Drivetrain Systems
8W-40 thru
8W-49Body Electrical items and A/C
8W-50 thru
8W-59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru
8W-69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
8W - 01 - 6 8W-01 WIRING DIAGRAM INFORMATIONDR
WIRING DIAGRAM INFORMATION (Continued)

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).
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.
(4) Unplug the compressor clutch relay from the
PDC.
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
The A/C heater system uses a seriers of electrical
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 manual in the vehicle glove box for more
information on the features, use, and suggested oper-
ation of these controls.
The A/C heater control - (Single Zone) or (Dual
Zone) panel is located to the right of the instrument
cluster on the instrument panel.
The control panel contains a rotary-type tempera-
ture control, a rotary-type mode control switch knob,
and a rotary-type blower motor speed switch knob.
The control also has a push button to activate the
Optional side view mirrors defroster elements and to
turn the A/C on.
The Dual Zone HVAC control panel contains a pair
of slider-type temperature controls, a rotary-type
mode control switch knob and a rotary-type blower
motor speed switch knob. The control also has but-
tons to turn the A/C ON, Set it on Max A/C and for
the Optional Heated Sideview Mirrors.The A/C heater control panel cannot be repaired. If
faulty or damaged, the entire unit must be replaced.
The illumination lamps are available 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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center bezel from the instrument
panel(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL CENTER BEZEL - REMOVAL).
(3) Remove the screws that secure the A/C Heater
control to the instrument panel (Fig. 11) or (Fig. 12).
(4) Pull the A/C Heater control assembly away
from the instrument panel far enough to access the
connections on the back of the control.
(5) Unplug the wire harness connectors from the
back of the A/C Heater control (Fig. 13).
Fig. 11 Single Zone HVAC Control
1 - Mounting Tab (4)
2 - A/C Button
3 - Sideview Mirror Defroster Button (if equiped)
4 - Mode Control
5 - Blend Air Control
6 - Blower Motor Speed Control
24 - 14 CONTROLSDR
A/C COMPRESSOR CLUTCH RELAY (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
AIR OUTLETS
REMOVAL - PANEL OUTLETS.............24
INSTALLATION - PANEL OUTLETS..........24
BLEND DOOR
REMOVAL.............................24
INSTALLATION.........................25
BLOWER MOTOR
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - BLOWER
MOTOR .............................26
REMOVAL.............................26
INSTALLATION.........................26
DEFROST DOOR
REMOVAL - DEFROST DOOR.............27
INSTALLATION - DEFROST DOOR..........27
FLOOR DISTRIBUTION DUCTS
REMOVAL.............................27INSTALLATION.........................27
HVAC HOUSING
REMOVAL.............................27
DISASSEMBLY.........................28
ASSEMBLY............................28
INSTALLATION.........................29
INSTRUMENT PANEL DUCTS
REMOVAL.............................29
INSTALLATION.........................29
MODE DOOR
REMOVAL - FLOOR - DEFROST DOOR......30
INSTALLATION - FLOOR - DEFROST DOOR . . 30
RECIRC DOOR
REMOVAL.............................30
INSTALLATION.........................30
AIR OUTLETS
REMOVAL - PANEL OUTLETS
(1) Use a trim stick or another suitable wide flat-
bladed tool to gently pry the panel outlet grill out of
the panel outlet housing (Fig. 1). The panel outlet
grill is retained by a light snap fit.
INSTALLATION - PANEL OUTLETS
To install, position the grill housing in the panel
outlet housing and press firmly until it snaps into
place.
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.
Fig. 1 Dash Panel
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 Control Switch (if equipped)
10 - Cigar Lighter
11 - Cup Holders
12 - Ash Tray (if equipped)
13 - Power Outlet
24 - 24 DISTRIBUTIONDR