HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
2. Loose or worn generator drive belt. 2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system. Refer to
Group 8A.
4. Battery has insufficient charge. 4. Test battery state-of -charge. Refer to
Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group 8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
7. Low beam headlamp / foglamp fuse
blown.7. Locate cause of blown fuse and repair.
HEADLAMP BULBS BURN
OUT FREQUENTLY1. Charging system output too high. 1. Test and repair charging system. Refer to
Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer to
Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
3. High resistance in headlamp circuit. 3. Test amperage draw of headlamp circuit.
4. Low beam headlamp / fog lamp
fuse blown.4. Locate cause of blown fuse and repair.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
2. High resistance in headlamp circuit. 2. Test amperage draw of headlamp circuit.
3. Loose or corroded terminals or
splices in circuit.3. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS DO NOT
ILLUMINATE1. No voltage to headlamps. 1. Repair open headlamp circuit. Refer to
Group 8W.
2. No Z1-ground at headlamps. 2. Repair circuit ground. Refer to Group 8W.
3. Faulty headlamp switch. 3. Replace headlamp switch.
4. Faulty headlamp dimmer (multi-
function) switch.4. Replace multi-function switch.
5. Broken connector terminal or wire
splice in headlamp circuit.5. Repair connector terminal or wire splice.
6. Defective or burned out bulb. 6. Replace bulb.
7. Body controller malfunction. 7. Refer to appropriate body controller
diagnostics.
NSLAMPS 8L - 3
DIAGNOSIS AND TESTING (Continued)
FOG LAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM WITH
ENGINE IDLING OR IGNITION
TURNED OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable
clamps and posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive
belt.
3. Charging system output too low. 3. Test and repair charging system.
Refer to Group 8A,
4. Battery has insufficient charge. 4. Test battery state-of -charge.
Refer to Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group
8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
FOG LAMP BULBS BURN OUT
FREQUENTLY1. Charging system output too high. 1. Test and repair charging system.
Refer to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS ARE DIM WITH
ENGINE RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system.
Refer to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp
circuit.
FOG LAMPS FLASH RANDOMLY 1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
2. High resistance in fog lamp
circuit.2. Test amperage draw of fog lamp
circuit.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS DO NOT ILLUMINATE 1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Group
8W.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to
Group 8W.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Broken connector terminal or
wire splice in fog lamp circuit.4. Repair connector terminal or wire
splice.
5. Defective or burned out bulb. 5. Replace bulb.
8L - 4 LAMPSNS
DIAGNOSIS AND TESTING (Continued)
HEADLAMP LEVELING MOTOR
This vehicle is equipped with a remote headlamp
leveling system. This system allows the driver to
adjust the vertical headlamp aim from the interior of
the vehicle to compensate for passenger or cargo
load. A headlamp leveling switch is located in the
instrument panel and controls the headlamp leveling
motor found on the back of the headlamp module.
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES
When a vehicle experiences problems with the head-
lamp system, verify the condition of the battery connec-
tions, charging system, headlamp bulbs, wire
connectors, relay, high beam dimmer switch and head-
lamp switch. Refer to Group 8W, Wiring Diagrams, for
component locations and circuit information.
HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
2. Loose or worn alternator drive
belt.2. Adjust or replace alternator drive belt.
3. Charging system output too low. 3. Test and repair charging system. Refer
to Group 8A.
4. Battery has insufficient charge. 4. Test battery state-of -charge. Refer to
Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group 8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
HEADLAMP BULBS BURN
OUT FREQUENTLY1. Charging system output too high. 1. Test and repair charging system. Refer
to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer
to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
2. High resistance in headlamp
circuit.2. Test amperage draw of headlamp circuit.
3. Loose or corroded terminals or
splices in circuit.3. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS DO NOT
ILLUMINATE1. No voltage to headlamps. 1. Repair open headlamp circuit. Refer to
Group 8W.
2. No Z1-ground at headlamps. 2. Repair circuit ground. Refer to Group
8W.
3. Faulty headlamp switch. 3. Replace headlamp switch.
4. Faulty headlamp dimmer
(multi-function) switch.4. Replace multi-function switch.
5. Broken connector terminal or wire
splice in headlamp circuit.5. Repair connector terminal or wire splice.
6. Defective or burned out bulb. 6. Replace bulb.
7. Body controller malfunction. 7. Refer to appropriate body controller
diagnostics.
8L - 2 LAMPSNS/GS
GENERAL INFORMATION (Continued)
FOG LAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM WITH
ENGINE IDLING OR IGNITION
TURNED OFF.1. Loose or corroded battery cables. 1. Clean and secure battery cable
clamps and posts.
2. Loose or worn alternator drive
belt.2. Adjust or replace alternator drive
belt.
3. Charging system output too low. 3. Test and repair charging system.
Refer to Group 8A,
4. Battery has insufficient charge. 4. Test battery state-of -charge.
Refer to Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group
8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
FOG LAMP BULBS BURN OUT
FREQUENTLY1. Charging system output too high. 1. Test and repair charging system.
Refer to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS ARE DIM WITH
ENGINE RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system.
Refer to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp
circuit.
FOG LAMPS FLASH RANDOMLY 1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
2. High resistance in fog lamp
circuit.2. Test amperage draw of fog lamp
circuit.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Group 8W.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to
Group 8W.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Broken connector terminal or wire
splice in fog lamp circuit.4. Repair connector terminal or wire
splice.
5. Defective or burned out bulb. 5. Replace bulb.
NS/GSLAMPS 8L - 3
DIAGNOSIS AND TESTING (Continued)
THERMOMETER AND COMPASS
THERMOMETER
Engine temperature can increase the displayed
temperature. The CMTC is designed to dampen tem-
perature readings when the vehicle is moving at a
rate slower than 18 miles per hour.
The outside temperature is measured from a sen-
sor mounted in the front of the vehicle. If the tem-
perature is more than 55ÉC (131ÉF) or the
temperature sending line is shorted to ground, the
temperature display should read SC. If the tempera-
ture is less than -40ÉC (-40ÉF), or the sending line is
an open circuit, the display should read OC.
The CMTC will not allow the temperature reading
to increase when the vehicle is not moving.
COMPASS
The CMTC is self calibrating and usually requires
no adjustment. The compass will continuously per-
form a slow calibration to compensate for small mag-
netic variations common to any automobile.
Uncommon magnetic shifts may be caused by items
such as magnetic base antennas, which can perma-
nently alter the magnetic field of the vehicle roof
panel. If excessive magnetic field continues for 5 min-
utes, the compass heading will go blank and only the
CAL symbol will illuminate. When this occurs, the
vehicle roof panel may require demagnetizing. Refer
to the demagnetizing procedure in this section.
Moderate magnetic shifts may, on very rare occa-
sions, cause the compass heading to display only one
or two of the eight possible headings. Although the
compass will eventually compensate for this shift, it
could take several ignition cycles. The compensation
process can be expedited by manually activating the
fast calibration routine. Refer to the fast calibrating
procedure in this section. This procedure may be per-formed anytime that the compass appears to be inac-
curate.
If the calibration data stored in the body control
module is not received, the compass will read only
NE North-East. The CMTC is self calibrating and
requires no adjusting. The word CAL is displayed to
show that the compass is in calibration mode. CAL
will turn off after the vehicle has gone through three
complete circles without stopping, in an area free of
magnetic disturbance. If module displays tempera-
ture while the compass is blank, turn off ignition and
run self diagnostics then demagnetize the vehicle.
After demagnetizing, check compass calibration num-
ber, refer to Self Diagnostic Test. If greater than 15,
demagnetize again until reading is less than 15. If
compass still goes blank after demagnetizing then
check internal diagnostics and demagnetize.
UNIVERSAL TRANSMITTER
The Universal Transmitter, replaces the hand held
remote controls that open the garage door, motorized
gates, or home lighting in/outside the home. This
device memorizes the activator codes for up to three
remote controlled devices. It triggers those devices at
the push of a button, located in a unit permanently
mounted in your overhead console (if equipped).
The transmitter operates off your vehicle's battery
and charging system; no batteries are needed.
The Universal Transmitter incorporates a Rolling
Code technology (random digital code signals from
the remote transmitter) within the transmitter mod-
ule. This is done so, as an added security measure.
Features of the Universal Transmitter are:
²Can be used with most other Radio Frequency
(RF) activated devices.
²Individual channels can be trained.
Fig. 1 Compass Mini-Trip Computer (CMTC)
Switches and Display
Fig. 2 Universal Transmitter Location
8V - 2 OVERHEAD CONSOLENS
DESCRIPTION AND OPERATION (Continued)
WIRING DIAGRAMS
CONTENTS
page page
AIR CONDITIONING-HEATER.......... 8W-42-1
AIRBAG SYSTEM................... 8W-43-1
ANTI-LOCK BRAKES................. 8W-35-1
AUDIO SYSTEM.................... 8W-47-1
BODY CONTROL MODULE............ 8W-45-1
CHARGING SYSTEM................. 8W-20-1
COMPONENT INDEX................. 8W-02-1
CONNECTOR/GROUND LOCATIONS..... 8W-90-1
CONNECTOR PIN-OUTS.............. 8W-80-1
FRONT LIGHTING................... 8W-50-1
FUEL/IGNITION SYSTEM............. 8W-30-1
GENERAL INFORMATION............. 8W-01-1
GROUND DISTRIBUTION............. 8W-15-1
HORN/CIGAR LIGHTER/POWER OUTLET . 8W-41-1
INSTRUMENT CLUSTER.............. 8W-40-1
INTERIOR LIGHTING................. 8W-44-1
JUNCTION BLOCK................... 8W-12-1
MESSAGE CENTER.................. 8W-46-1OVERHEAD CONSOLE................ 8W-49-1
POWER DISTRIBUTION.............. 8W-10-1
POWER DOOR LOCKS............... 8W-61-1
POWER MIRRORS.................. 8W-62-1
POWER SEAT...................... 8W-63-1
POWER WINDOWS.................. 8W-60-1
REAR LIGHTING.................... 8W-51-1
SPLICE INFORMATION............... 8W-70-1
SPLICE LOCATIONS................. 8W-95-1
STARTING SYSTEM................. 8W-21-1
TRAILER TOW...................... 8W-54-1
TRANSMISSION CONTROL SYSTEM.... 8W-31-1
TURN SIGNALS..................... 8W-52-1
VEHICLE SPEED CONTROL........... 8W-33-1
VEHICLE THEFT SECURITY SYSTEM.... 8W-39-1
WINDOW DEFOGGERS............... 8W-48-1
WIPERS........................... 8W-53-1
NS/GSWIRING DIAGRAMS 8W - 1
SECTION IDENTIFICATION
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.
SYMBOLS
International symbols are used throughout the wir-
ing diagrams. These symbols are consistent with
those being used around the world.
GROUP TOPIC
8W-01 thru 8W-09 General Information and
Diagram Overview
8W-10 thru 8W-19 Main Sources of Power and
Vehicle Grounding
8W-20 thru 8W-29 Starting and Charging
8W-30 thru 8W-39 Powertrain/Drivetrain
Systems
8W-40 thru 8W-49 Body Electrical items and A/C
8W-50 thru 8W-59 Exterior Lighting, Wipers, and
Trailer Tow
8W-60 thru 8W-69 Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-90 Connector Locations
(including grounds)
8W-95 Splice Locations
NS/GS8W-01 GENERAL INFORMATION 8W - 01 - 5
DESCRIPTION AND OPERATION (Continued)
8W-20 CHARGING SYSTEM
Component Page
Automatic Shut Down Relay.............8W-20-2
Battery...........................8W-20-2, 3
BS33...............................8W-20-3
Diesel Power Relay....................8W-20-3
Engine Starter Motor................8W-20-2, 3
ES01...............................8W-20-3
ES06...............................8W-20-3
ES09...............................8W-20-2
ES11 .............................8W-20-2, 3
ES12...............................8W-20-2
ES26...............................8W-20-3Component Page
ES28...............................8W-20-3
Fuse 17 (PDC)......................8W-20-2, 3
Fusible Link.......................8W-20-2, 3
G100.............................8W-20-2, 3
G103.............................8W-20-2, 3
Generator.........................8W-20-2, 3
Glow Plug Relay......................8W-20-3
Power Distribution Center.............8W-20-2, 3
Powertrain Control Module............8W-20-2, 3
Voltage Regulator.....................8W-20-3
NS/GS8W - 20 CHARGING SYSTEM 8W - 20 - 1