1998 DODGE RAM 1500 Ignition wire harness

AIRBAG CONTROL MODULE
DESCRIPTION
The Airbag Control Module (ACM) is also some-
times referred to as the Occupant Restraint Control-
ler (ORC) (Fig. 7). The ACM is concealed below the
instrument panel center stack in the passenger com-
partment of the vehicle, where it is secured by three
screws to a stamped steel mounting bracket welded
onto the top of the floor panel transmission tunnel
just forward of the instrument panel center support
bracket. Concealed within a hollow in the center of
the die cast aluminum ACM housing is the electronic
circuitry of the ACM which includes a microproces-
sor, an electronic impact sensor, an electronic safing
sensor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ACM housing with four screws to enclose and protect
the internal electronic circuitry and components.
An arrow printed on the label on the top of the
ACM housing provides a visual verification of the
proper orientation of the unit, and should always be
pointed toward the front of the vehicle. The ACM
housing has integral mounting flanges on three cor-
ners. The mounting flange to the left of the connector
receptacle has an integral locating pin on its lower
surface. Both left side flanges have round mounting
holes, while the flange on the right side has a slotted
mounting hole. A molded plastic electrical connector
with two receptacles, one containing twenty-four ter-
minal pins and the other containing thirty-two termi-
nal pins, exits the rearward facing side of the ACM
housing. These terminal pins connect the ACM to the
vehicle electrical system through two dedicated takeouts and connectors of the instrument panel wire
harness.
The impact sensor and safing sensor internal to
the ACM are calibrated for the specific vehicle, and
are only serviced as a unit with the ACM. In addi-
tion, there are unique versions of the ACM for light
and heavy-duty models, and for vehicles with or
without the optional side curtain airbags. The ACM
cannot be repaired or adjusted and, if damaged or
faulty, it must be replaced.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the supplemental restraint system
logic circuits and controls all of the supplemental
restraint system components. The ACM uses
On-Board Diagnostics (OBD) and can communicate
with other electronic modules in the vehicle as well
as with the DRBIIItscan tool using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used for
control of the airbag indicator in the ElectroMechani-
cal Instrument Cluster (EMIC) and for supplemental
restraint system diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER/AIRBAG
INDICATOR - OPERATION).
The ACM microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ACM
detects a monitored system fault, it sets an active
and stored Diagnostic Trouble Code (DTC) and sends
electronic messages to the EMIC over the PCI data
bus to turn on the airbag indicator. An active fault
only remains for the duration of the fault, or in some
cases for the duration of the current ignition switch
cycle, while a stored fault causes a DTC to be stored
in memory by the ACM. For some DTCs, if a fault
does not recur for a number of ignition cycles, the
ACM will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
In standard cab models, the ACM also monitors a
resistor multiplexed input from the passenger airbag
on/off switch and provides a control output for the
Off indicator in the switch through a passenger air-
bag indicator driver circuit. If the passenger airbag
on/off switch is set to the Off position, the ACM turns
on the passenger airbag on/off switch Off indicator
and will internally disable the passenger airbag from
being deployed. The ACM also turns on the on/off
switch Off indicator for about seven seconds each
time the ignition switch is turned to the On position
as a bulb test. Following the bulb test, the ACM con-
trols the status of the Off indicator based upon the
Fig. 7 Airbag Control Module
1 - AIRBAG CONTROL MODULE
2 - ORIENTATION ARROW
3 - LABEL
4 - CONNECTOR RECEPTACLE (2)
DRRESTRAINTS 8O - 11

resistance of the input from the on/off switch. The
ACM will also set and/or store a DTC for faults it
detects in the passenger airbag on/off switch circuits,
and will turn on the airbag indicator in the EMIC if
a fault has been detected.
The ACM receives battery current through two cir-
cuits; a fused ignition switch output (run) circuit
through a fuse in the Integrated Power Module
(IPM), and a fused ignition switch output (run-start)
circuit through a second fuse in the IPM. The ACM
receives ground through a ground circuit and take
out of the instrument panel wire harness. This take
out has a single eyelet terminal connector that is
secured by a ground screw to the instrument panel
support structure. These connections allow the ACM
to be operational whenever the ignition switch is in
the Start or On positions.
The ACM also contains an energy-storage capaci-
tor. When the ignition switch is in the Start or On
positions, this capacitor is continually being charged
with enough electrical energy to deploy the supple-
mental restraint components for up to one second fol-
lowing a battery disconnect or failure. The purpose of
the capacitor is to provide backup supplemental
restraint system protection in case there is a loss of
battery current supply to the ACM during an impact.
Two sensors are contained within the ACM, an
electronic impact sensor and a safing sensor. The
electronic impact sensors are accelerometers that
sense the rate of vehicle deceleration, which provide
verification of the direction and severity of an
impact. On models equipped with optional side cur-
tain airbags, the ACM also monitors inputs from two
remote side impact sensors located within both the
left and right B-pillars to control deployment of the
side curtain airbag units.
The safing sensor is an electronic accelerometer
sensor within the ACM that provides an additional
logic input to the ACM microprocessor. The safing
sensor is used to verify the need for a supplemental
restraint deployment by detecting impact energy of a
lesser magnitude than that of the primary electronic
impact sensors, and must exceed a safing threshold
in order for the airbags to deploy. Vehicles equipped
with optional side curtain airbags feature a second
safing sensor within the ACM to provide confirma-
tion to the ACM microprocessor of side impact forces.
This second safing sensor is a bi-directional unit that
detects impact forces from either side of the vehicle.
Pre-programmed decision algorithms in the ACM
microprocessor determine when the deceleration rate
as signaled by the impact sensors and the safing sen-
sors indicate an impact that is severe enough to
require supplemental restraint system protection
and, based upon the severity of the monitored impact
and the status of the passenger airbag on/off switchinput, determines the level of front airbag deploy-
ment force required for each front seating position.
When the programmed conditions are met, the ACM
sends the proper electrical signals to deploy the dual
multistage front airbags at the programmed force
levels, the front seat belt tensioners and, if the vehi-
cle is so equipped, either side curtain airbag unit.
The hard wired inputs and outputs for the ACM
may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods will not prove conclusive in
the diagnosis of the ACM, the PCI data bus network,
or the electronic message inputs to and outputs from
the ACM. The most reliable, efficient, and accurate
means to diagnose the ACM, the PCI data bus net-
work, and the electronic message inputs to and out-
puts from the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, NEVER STRIKE OR DROP THE AIRBAG
CONTROL MODULE, AS IT CAN DAMAGE THE
IMPACT SENSOR OR AFFECT ITS CALIBRATION.
THE AIRBAG CONTROL MODULE CONTAINS THE
IMPACT SENSOR, WHICH ENABLES THE SYSTEM
TO DEPLOY THE SUPPLEMENTAL RESTRAINTS. IF
AN AIRBAG CONTROL MODULE IS ACCIDENTALLY
DROPPED DURING SERVICE, THE MODULE MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER SUPPLEMENTAL RESTRAINT DEPLOY-
MENT.
8O - 12 RESTRAINTSDR
AIRBAG CONTROL MODULE (Continued)

The passenger airbag on/off switch housing is con-
structed of molded plastic and has three integral
mounting tabs. These mounting tabs are used to
secure the switch to the back of the molded plastic
switch face plate with three small screws. The
molded plastic face plate also has three integral
mounting tabs that are used to secure the switch and
face plate unit to the instrument panel center bezel
with three additional screws. A molded plastic con-
nector receptacle on the back of the switch housing
connects the switch to the vehicle electrical system
through a dedicated take out and connector of the
instrument panel wire harness. The molded plastic
harness connector insulator is keyed and latched to
ensure proper and secure switch electrical connec-
tions. The passenger airbag on/off switch cannot be
adjusted or repaired and, if faulty or damaged, the
switch must be replaced.
OPERATION
The passenger airbag on/off switch allows the cus-
tomer to turn the passenger airbag function On or
Off to accommodate certain uses of the right front
seating position where airbag protection may not be
desired. See the owner's manual in the vehicle glove
box for specific recommendations on when to enable
or disable the passenger airbag. The Off indicator of
the switch will be illuminated whenever the switch is
turned to the Off position and the ignition switch is
in the On position.
The ignition key is the only key or object that
should ever be inserted into the key cylinder actuator
of the switch. The on/off switch requires only a par-
tial key insertion to fully depress a spring-loaded
locking plunger. The spring-loaded locking plunger
prevents the user from leaving the key in the switch.
The key will be automatically ejected when force is
not applied. To actuate the passenger airbag on/off
switch, insert the ignition key into the switch key
actuator far enough to fully depress the plunger, then
rotate the actuator to the desired switch position.
When the switch key actuator is rotated to its clock-
wise stop (the key actuator slot will be aligned with
the Off indicator), the Off indicator is illuminated
and the passenger airbag is disabled. When the
switch is rotated to its counterclockwise stop (the key
actuator slot will be in a vertical position), the Off
indicator will be extinguished and the passenger air-
bag is enabled.The passenger airbag on/off switch connects one of
two internal resistors in series between the passen-
ger airbag mux switch sense and passenger airbag
mux switch return circuits of the Airbag Control
Module (ACM). The ACM continually monitors the
resistance in these circuits to determine the switch
position that has been selected. When the switch is
in the Off position, the ACM provides a ground input
to the switch through the passenger airbag indicator
driver circuit, which energizes the Light-Emitting
Diode (LED) that illuminates the Off indicator of the
switch.
The ACM will also illuminate the Off indicator of
the switch for about seven seconds each time the
ignition switch is turned to the On position as a bulb
test. The ACM will store a Diagnostic Trouble Code
(DTC) for any fault it detects in the passenger airbag
on/off switch or Off indicator circuits, and will illumi-
nate the airbag indicator in the instrument cluster if
a fault is detected. For proper diagnosis of the pas-
senger airbag on/off switch or the ACM, a DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
REMOVAL
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the center bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL).
(3) From the back of the center bezel, remove the
three screws that secure the passenger airbag on/off
switch and face plate unit to the back of the bezel
(Fig. 40).
(4) Remove the passenger airbag on/off switch and
face plate from the center bezel as a unit.
DRRESTRAINTS 8O - 43
PASSENGER AIRBAG ON/OFF SWITCH (Continued)

retracted or extracted is a sure indication that the
seat belt tensioner has been deployed and requires
replacement. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/FRONT OUTBOARD SEAT BELT &
RETRACTOR - REMOVAL).
OPERATION
The seat belt tensioners are deployed by a signal
generated by the Airbag Control Module (ACM)
through the driver and passenger seat belt tensioner
line 1 and line 2 (or squib) circuits. When the ACM
sends the proper electrical signal to the tensioners,
the electrical energy generates enough heat to ini-
tiate a small pyrotechnic gas generator. The gas gen-
erator is installed at the top of the tensioner housing
which contains a long metal tape that is routed
through two chambers within the housing. Each end
of the tape is wound around the outer sleeve of a
mechanical clutch mechanism secured to one end of
the torsion bar upon which the retractor spool is
secured. As the gas expands, it is directed against
the metal tape within the two chambers of the hous-
ing causing the tape to unwind from the clutch
sleeve. As the clutch rotates it engages the torsion
bar, which drives the seat belt retractor spool causing
the slack to be removed from the seat belt.
Once a seat belt tensioning sequence has been
completed, the forward momentum of the occupant
results in deformation of the torsion bar. As the tor-
sion bar deforms it allows the seat belt webbing to
unwind from the retractor spool, which causes the
metal tape to be wound back onto the clutch sleeve
until it is pulled tight against two cutter blades
within the housing, which immediately cut the metal
tape.
Removing excess slack from the seat belt not only
keeps the occupant properly positioned for an airbag
deployment following a frontal impact of the vehicle,
but also helps to reduce injuries that the occupant
might experience in these situations as a result of a
harmful contact with the steering wheel, steering col-
umn, instrument panel and/or windshield. The tor-
sion bar is designed to deform in order to control the
loading being applied to the occupant by the seat belt
during a frontal impact, further reducing the poten-
tial for occupant injuries.
The ACM monitors the condition of the seat belt
tensioners through circuit resistance. The ACM will
illuminate the airbag indicator in the ElectroMe-
chanical Instrument Cluster (EMIC) and store a
Diagnostic Trouble Code (DTC) for any fault that is
detected. For proper diagnosis of the seat belt ten-
sioners, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
SEAT BELT TENSION
REDUCER
DESCRIPTION
A seat belt tension reducer is standard equipment
for the driver side front outboard seat belt on stan-
dard cab versions of this model (Fig. 49). The tension
reducer is integral to the driver side front outboard
seat belt and retractor unit, which is secured to the
inner B-pillar on the left side of the vehicle. The
retractor is concealed beneath the molded plastic
inner B-pillar trim. The seat belt tension reducer
consists primarily of a 12-volt Direct Current (DC)
solenoid and an integral connector receptacle that is
located on the forward facing end housing of the
retractor. The seat belt tension reducer is controlled
by a battery current output of the ignition switch and
a ground path provided by the seat belt switch, and
is connected to the vehicle electrical system through
a dedicated take out of the body wire harness by a
keyed and latching molded plastic connector insula-
tor to ensure a secure connection.
The seat belt tension reducer cannot be repaired
and, if faulty or damaged, the entire driver side front
outboard seat belt and retractor unit must be
replaced. (Refer to 8 - ELECTRICAL/RESTRAINTS/
FRONT OUTBOARD SEAT BELT & RETRACTOR -
REMOVAL).
Fig. 49 Seat Belt Tension Reducer
1 - TENSIONER HOUSING OR CHAMBER
2 - GAS GENERATOR
3 - TENSIONER PIGTAIL WIRE
4 - SPOOL
5 - TENSION REDUCER (DRIVER SIDE ON STANDARD CAB
ONLY)
6 - REDUCER CONNECTOR RECEPTACLE
DRRESTRAINTS 8O - 53
SEAT BELT TENSIONER (Continued)

OPERATION
The seat belt tension reducer is controlled by a
ground signal received from the seat belt switch on
the seat belt switch sense circuit and a battery cur-
rent signal received from the ignition switch on the
fused ignition switch output (run-accessory) circuit.
When the seat belt switch is closed (the driver side
front seat belt is fastened) and the ignition switch is
in the On or Accessory positions, the seat belt tension
reducer solenoid is energized. When the solenoid is
energized, it actuates a mechanism within the driver
side front outboard seat belt retractor to reduce the
normal recoil spring tension exerted by the retractor
spool, which is designed to reel in the seat belt web-
bing onto the spool. When the driver side seat belt is
unbuckled or if the ignition switch is turned to any
position except On or Accessory, the tension reducer
solenoid is de-energized and the normal recoil spring
tension of the retractor is restored.
The action of the seat belt tension reducer results
in improved seat belt comfort for the driver. Reducing
the seat belt retractor recoil spring tension is desir-
able on standard cab models of this vehicle and not
on the quad cab model due to the different mounting
position required for the seat belt turning loop on the
B-pillar relative to the driver's seat position on the
standard cab model. The seat belt tension reducer
may be diagnosed using conventional diagnostic tools
and methods.
DIAGNOSIS AND TESTING - SEAT BELT
TENSION REDUCER
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the seat belt tension reducer from the tension
reducer connector receptacle on the driver side front
outboard seat belt and retractor unit. Using an ohm-
meter, measure the resistance between the seat belt
switch sense circuit terminal pin and the fused igni-
tion switch output (run-accessory) circuit terminal
pin in the tension reducer connector receptacle on
the retractor. Resistance through the tension reducer
solenoid coil should be 53 ohms at 20É C (68É F). If
OK, go to Step 2. If not OK, replace the faulty driver
side front outboard seat belt and retractor unit.
(2) Check for continuity between the seat belt
switch sense circuit cavity of the body wire harness
connector for the seat belt tension reducer and a good
ground. There should be continuity with the driver
side front seat belt buckled, and no continuity with
the driver side front seat belt unbuckled. If OK, go to
Step 3. If not OK, repair the shorted or open seat
belt switch sense circuit between the tension reducer
and the seat belt switch as required.
(3) Reconnect the battery negative cable. Check for
battery current at the fused ignition switch output
(run-accessory) circuit of the body wire harness con-
nector for the seat belt tension reducer. There should
be battery current with the ignition switch in the On
or Accessory positions, and no battery current with
the ignition switch in any other position. If not OK,
repair the shorted or open fused ignition switch out-
put (run-accessory) circuit between the tension
reducer and the ignition switch as required.
8O - 54 RESTRAINTSDR
SEAT BELT TENSION REDUCER (Continued)

The wiper on/off relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper on/off relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put to the wiper motor. The movable common feed
contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The wiper on/off relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Integrated Power Module (IPM).
The inputs and outputs of the wiper on/off relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the common feed termi-
nal of the wiper high/low relay at all times through
the wiper on/off relay output circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a wiper on/off relay
control circuit. The FCM controls wiper motor opera-
tion by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the IPM through a fused ignition switch
output (run-acc) circuit.
²Normally Open Terminal- The normally open
terminal (87) receives battery current at all times
from a fuse in the IPM through a fused ignition
switch output (run-acc) circuit, and provides battery
current to the wiper on/off relay output circuit when-
ever the relay is energized.²Normally Closed Terminal- The normally
closed terminal (87A) is connected to ground at all
times through a take out of the left headlamp and
dash wire harness with an eyelet terminal connector
that is secured by a screw to the front end sheet
metal, and is connected to the wiper on/off relay out-
put circuit whenever the relay is de-energized.
The wiper on/off relay may be diagnosed using con-
ventional diagnostic tools and methods. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the instrument cluster, the
Front Control Module (FCM), or the electronic mes-
sage inputs to or outputs from the instrument cluster
and the FCM that control the operation of the wiper
on/off relay. The most reliable, efficient, and accurate
means to diagnose the wiper on/off relay, the instru-
ment cluster, the FCM, or the electronic message
inputs and outputs related to the wiper on/off relay
operation requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY
The wiper on/off relay (Fig. 28) is located in the
Integrated Power Module (IPM) in the engine com-
partment near the battery. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
Fig. 28 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DRWIPERS/WASHERS 8R - 25
WIPER ON/OFF RELAY (Continued)

8W-01 WIRING DIAGRAM INFORMATION
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION
DESCRIPTION
DESCRIPTION - HOW TO USE WIRING
DIAGRAMS...........................1
DESCRIPTION - CIRCUIT INFORMATION....5
DESCRIPTION - CIRCUIT FUNCTIONS......6
DESCRIPTION - SECTION IDENTIFICATION
AND INFORMATION....................6
DESCRIPTION - CONNECTOR, GROUND
AND SPLICE INFORMATION..............7
WARNING
WARNINGS - GENERAL.................7
DIAGNOSIS AND TESTING - WIRING
HARNESS............................7
STANDARD PROCEDURE
STANDARD PROCEDURE -
ELECTROSTATIC DISCHARGE (ESD)
SENSITIVE DEVICES...................8
STANDARD PROCEDURE - TESTING OF
VOLTAGE POTENTIAL...................9
STANDARD PROCEDURE - TESTING FOR
CONTINUITY..........................9STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND...................9
STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND ON FUSES
POWERING SEVERAL LOADS...........10
STANDARD PROCEDURE - TESTING FOR A
VOLTAGE DROP......................10
SPECIAL TOOLS
WIRING/TERMINAL....................10
CONNECTOR
REMOVAL.............................11
INSTALLATION.........................11
DIODE
REMOVAL.............................14
INSTALLATION.........................14
TERMINAL
REMOVAL.............................14
INSTALLATION.........................14
WIRE
STANDARD PROCEDURE - WIRE SPLICING . . 15
WIRING DIAGRAM
INFORMATION
DESCRIPTION
DESCRIPTION - HOW TO USE WIRING
DIAGRAMS
DaimlerChrysler Corporation wiring diagrams are
designed to provide information regarding the vehi-
cles wiring content. In order to effectively use the
wiring diagrams to diagnose and repair
DaimlerChrysler Corporation vehicles, it is important
to understand all of their features and characteris-
tics.
Diagrams are arranged such that the power (B+)
side of the circuit is placed near the top of the page,
and the ground (B-) side of the circuit is placed near
the bottom of the page (Fig. 1).
All switches, components, and modules are shown
in the at rest position with the doors closed and the
key removed from the ignition (Fig. 2).Components are shown two ways. A solid line
around a component indicates that the component is
complete. A dashed line around the component indi-
cates that the component is being shown is not com-
plete. Incomplete components have a reference
number to indicate the page where the component is
shown complete.
It is important to realize that no attempt is made
on the diagrams to represent components and wiring
as they appear on the vehicle. For example, a short
piece of wire is treated the same as a long one. In
addition, switches and other components are shown
as simply as possible, with regard to function only.
SYMBOLS
International symbols are used throughout the wir-
ing diagrams. These symbols are consistent with
those being used around the world (Fig. 3).
DR8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 1

DESCRIPTION - CONNECTOR, GROUND AND
SPLICE INFORMATION
CAUTION: Not all connectors are serviced. Some
connectors are serviced only with a harness. A typ-
ical example might be the Supplemental Restraint
System connectors. Always check parts availability
before attempting a repair.
IDENTIFICATION
In-line connectors are identified by a number, as
follows:
²In-line connectors located in the engine compart-
ment are C100 series numbers
²In-line connectors located in the Instrument
Panel area are C200 series numbers.
²In-line connectors located in the body are C300
series numbers.
²Jumper harness connectors are C400 series
numbers.
²Grounds and ground connectors are identified
with a ªGº and follow the same series numbering as
the in-line connectors.
²Splices are identified with an ªSº and follow the
same series numbering as the in-line connectors.
²Component connectors are identified by the com-
ponent name instead of a number. Multiple connec-
tors on a component use a C1, C2, etc. identifier.
LOCATIONS
Section 8W-91 contains connector/ground/splice
location illustrations. The illustrations contain the
connector name (or number)/ground number/splice
number and component identification. Connector/
ground/splice location charts in section 8W-91 refer-
ence the figure numbers of the illustrations.
The abbreviation T/O is used in the component
location section to indicate a point in which the wir-
ing harness branches out to a component. The abbre-
viation N/S means Not Shown in the illustrations
WARNING
WARNINGS - GENERAL
WARNINGSprovide information to prevent per-
sonal injury and vehicle damage. Below is a list of
general warnings that should be followed any time a
vehicle is being serviced.
WARNING: ALWAYS WEAR SAFETY GLASSES FOR
EYE PROTECTION.
WARNING: USE SAFETY STANDS ANYTIME A PRO-
CEDURE REQUIRES BEING UNDER A VEHICLE.WARNING: BE SURE THAT THE IGNITION SWITCH
ALWAYS IS IN THE OFF POSITION, UNLESS THE
PROCEDURE REQUIRES IT TO BE ON.
WARNING: SET THE PARKING BRAKE WHEN
WORKING ON ANY VEHICLE. AN AUTOMATIC
TRANSMISSION SHOULD BE IN PARK. A MANUAL
TRANSMISSION SHOULD BE IN NEUTRAL.
WARNING: OPERATE THE ENGINE ONLY IN A
WELL-VENTILATED AREA.
WARNING: KEEP AWAY FROM MOVING PARTS
WHEN THE ENGINE IS RUNNING, ESPECIALLY THE
FAN AND BELTS.
WARNING: TO PREVENT SERIOUS BURNS, AVOID
CONTACT WITH HOT PARTS SUCH AS THE RADIA-
TOR, EXHAUST MANIFOLD(S), TAIL PIPE, CATA-
LYTIC CONVERTER AND MUFFLER.
WARNING: DO NOT ALLOW FLAME OR SPARKS
NEAR THE BATTERY. GASES ARE ALWAYS
PRESENT IN AND AROUND THE BATTERY.
WARNING: ALWAYS REMOVE RINGS, WATCHES,
LOOSE HANGING JEWELRY AND AVOID LOOSE
CLOTHING.
DIAGNOSIS AND TESTING - WIRING HARNESS
TROUBLESHOOTING TOOLS
When diagnosing a problem in an electrical circuit
there are several common tools necessary. These tools
are listed and explained below.
²Jumper Wire - This is a test wire used to con-
nect two points of a circuit. It can be used to bypass
an open in a circuit.
WARNING: NEVER USE A JUMPER WIRE ACROSS
A LOAD, SUCH AS A MOTOR, CONNECTED
BETWEEN A BATTERY FEED AND GROUND.
²Voltmeter - Used to check for voltage on a cir-
cuit. Always connect the black lead to a known good
ground and the red lead to the positive side of the
circuit.
CAUTION: Most of the electrical components used
in today's vehicles are Solid State. When checking
voltages in these circuits, use a meter with a 10 -
megohm or greater impedance rating.
DR8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 7
WIRING DIAGRAM INFORMATION (Continued)