Turn and Lane-Change Signals
The turn signal has two upward (for right) and
two downward (for left) positions. These positions
allow you to signal a turn or a lane change.
To signal a turn, move the lever all the way up or
down. When the turn is finished, the lever will
return automatically.
An arrow on the
instrument panel cluster
will flash in the
direction of the turn or
lane change.
To signal a lane change, just raise or lower the
lever until the arrow starts to flash. Hold it
there until you complete your lane change. The
lever will return by itself when you release it.
As you signal a turn or a lane change, if the arrows
don’t flash but just stay on, check the turn signal
flasher and circuit breaker. SeeFuses and
Circuit Breakers on page 341.If a bulb is burned out, replace it to help avoid an
accident. If the arrows don’t go on at all when
you signal a turn, check the circuit breaker and for
burned-out bulbs.
Headlamp High/Low-Beam Changer
To change the headlamps from low to high
beam or high to low beam, pull the multifunction
lever all the way toward you, then release it.
When the high beams
are on, this light on the
instrument panel
cluster will also be on.
144
Accessory Power Outlet(s)
With accessory power outlets, you can plug in
auxiliary electrical equipment such as a cellular
telephone or CB radio.
The accessory power outlet is located on the
passenger’s side of the instrument panel.
To use an outlet, pull the cover down. When
not using it, always cover the outlet with the
protective cap.
This circuit is protected by a fuse and has a
maximum current level.
Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always
turn off electrical equipment when not in
use and do not plug in equipment that exceeds
the maximum amperage rating.
Certain electrical accessories may not be
compatible with the accessory power outlet and
could result in blown vehicle or adapter fuses.
If you experience a problem, see your dealer for
additional information on accessory power outlets.Notice:Adding any electrical equipment to
your vehicle may damage it or keep other
components from working as they should.
The repairs would not be covered by your
warranty. Do not use equipment exceeding
maximum amperage rating of 20 amperes.
Check with your dealer before adding electrical
equipment.
When adding electrical equipment, be sure to
follow the proper installation instructions included
with the equipment.
Notice:Improper use of the power outlet can
cause damage not covered by your warranty.
Do not hang any type of accessory or
accessory bracket from the plug because the
power outlets are designed for accessory
power plugs only.
156
Appearance Care........................................ 331
Cleaning the Inside of Your Vehicle.......... 331
Fabric/Carpet............................................. 333
Instrument Panel, Vinyl, and Other
Plastic Surfaces..................................... 334
Care of Safety Belts.................................. 334
Weatherstrips............................................ 334
Washing Your Vehicle............................... 335
Cleaning Exterior Lamps/Lenses................ 335
Finish Care............................................... 335
Windshield and Wiper Blades.................... 336
Aluminum or Chrome-Plated Wheels......... 337
Tires......................................................... 337
Sheet Metal Damage................................. 337
Finish Damage.......................................... 338
Underbody Maintenance............................ 338
Chemical Paint Spotting............................ 338Vehicle Identi cation.................................. 340
Vehicle Identification Number (VIN)........... 340
Service Parts Identification Label............... 340
Electrical System........................................ 340
Add-On Electrical Equipment..................... 340
Headlamp Wiring....................................... 341
Windshield Wiper Fuses............................ 341
Fusible Links............................................. 341
Power Windows and Other Power
Options.................................................. 341
Fuses and Circuit Breakers....................... 341
Instrument Panel Fuse Block..................... 342
Underhood Fuse Block.............................. 344
Capacities and Speci cations.................... 347
Normal Maintenance Replacement Parts..... 352
Engine Drive Belt Routing......................... 355
Section 5 Service and Appearance Care
247
Headlamp Wiring
The headlamp wiring is protected by a circuit
breaker in the light switch. An electrical overload
will cause the lights to go on and off, or in
some cases to remain off. If this happens, have
your headlamp wiring checked right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by a
circuit breaker inside the motor and a circuit
breaker or fuse in the fuse block. If the motor
overheats, the wipers will stop until the motor
cools. If the overload is caused by an electrical
problem, be sure to get it fixed.
Fusible Links
A fusible link is a short piece of wire several gauge
sizes smaller than the circuit it protects. It will melt
in an overload situation, opening the circuit.
Your starter and other circuits have these fusible
links. The size is printed on the insulation. If the
insulation is burned beyond recognition, consult
your dealer for the proper size. Replace a fusiblelink with one of the same size and insulation type.
Fusible link insulation is a special purpose
high-temperature material.
Some examples of circuits with fusible links are
the hydraulic brake booster motor feed circuit, the
generator output circuit, and the intake heater
feed circuit in vehicles with a diesel engine.
Power Windows and Other
Power Options
Circuit breakers in the fuse panel protect the power
windows and other power accessories. When the
current load is too heavy, the circuit breaker opens.
This protects the circuit until the current load returns
to normal or the problem is fixed.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected
from short circuits by a combination of fuses, circuit
breakers, maxi-fuses and fusible links. This greatly
reduces the chance of a fire caused by an electrical
problem. There may be a fuse taped to the wiring
harness near the hydraulic brake booster.
341
Instrument Panel Fuse Block
There are two instrument panel fuse blocks located behind the instrument panel on the passenger’s side of
the vehicle. Be sure to replace fuses with fuses of the same rating. Do not use fuses of higher amperage
than those indicated on the fuse block.
Fuse Usage
1 Stoplamps
2 Center High-Mounted Stoplamp
3 Parking LampsFuse Usage
4 Powertrain Control Module
5 Auxiliary Wiring
6 Heater/Air Conditioning
342
Relay Usage
ECU/PTO*Engine Control Unit/Power Take-Off
*Diesel 7.8 DURAMAX
®
BRK LAMPC4/C5 Brake Lamps,
C6/C7/C8 Tractor/Trailer Wiring
DRL Daytime Running Lamps
IGN-4 Ignition
CHMSL Center High Mounted Stoplamp
MRK LTS Sidemarker and Clearance Lamps
HTD/MIRR Heated Mirrors
HTR Diesel Heated Fuel
RT TRN TRLR Passenger’s Side Trailer Turn Signal
Blank Not Used
LT TRN TRLR Driver’s Side Trailer Turn Signal
Blank Not Used
Blank Not Used
Blank Not Used
Underhood Fuse Block
When a circuit goes out, the problem could be in
either the primary or secondary underhood
fuse blocks. These blocks use blade-type fuses.
Both underhood fuse blocks are located in
the engine compartment, on the passenger’s side
of the vehicle.
To access the fuse blocks, gently squeeze both
sides of the cover to unlatch the tabs at the
top. Then, unsnap both attachments at the bottom
and remove the cover.
Be sure to replace fuses with fuses of the same
rating. Do not use fuses of higher amperage
than those indicated on the fuse block.
344
E
Electrical System
Add-On Equipment................................... 340
Fuses and Circuit Breakers...................... 341
Fusible Links............................................ 341
Headlamp Wiring..................................... 341
Instrument Panel Fuse Block................... 342
Power Windows and Other Power
Options................................................. 341
Underhood Fuse Block............................. 344
Windshield Wiper Fuses........................... 341
Engine
Air Cleaner/Filter...................................... 280
Alarm and Automatic Shutdown................ 104
Battery..................................................... 304
Change Engine Oil Light.......................... 176
Check and Service Engine Soon Light..... 174
Checks Before Operating......................... 109
Coolant...........................................284, 287
Coolant Heater......................................... 111
Coolant Temperature Gage...................... 173
Diesel Engine Exhaust Brake................... 112
Drive Belt Routing.................................... 355
Exhaust................................................... 131
Exhaust Restrictor.................................... 108
Fan Breakage.......................................... 250Engine (cont.)
Fan Noise................................................ 294
High Idle System..................................... 106
Oil ...................................................268, 272
Oil Life System.......................276, 278, 279
Overheating............................................. 288
Overspeed Warning Light......................... 177
Reduced Power Light............................... 179
Shutdown Warning Light.......................... 177
Speed Limiter.......................................... 164
Starter Over-Crank Protection.................... 97
Starting Your Diesel................................. 100
Starting Your Gasoline............................... 97
Entry Lighting.............................................. 154
Event Data Recorders (EDR)...................... 409
Exhaust Brake Indicator Light...................... 178
Exhaust Restrictor....................................... 108
Extender, Safety Belt..................................... 41
Exterior Lamps............................................ 150
F
Filter
Engine Air Cleaner................................... 280
Filter Minder Gage...................................... 182
Finish Damage............................................ 338
Fixed Mast Antenna.................................... 204
421
Flashers, Hazard Warning........................... 142
Flat Tire...................................................... 330
Fluid
Automatic Transmission............................ 282
Manual Transmission................................ 283
Power Steering........................................ 295
Windshield Washer.................................. 296
Four-Wheel Drive...............................119, 312
Front Axle................................................... 313
Front Wheel Bearings with Oil-Filled Hubs ... 319
Fuel............................................................ 251
Additives.................................................. 252
Diesel Engine Fuel................................... 253
Filling a Portable Fuel Container.............. 266
Filling Your Tank...................................... 264
Filter........................................................ 317
Filter Replacement................................... 263
Fuels in Foreign Countries....................... 264
Gage....................................................... 181
Gasoline Octane...................................... 251
Gasoline Specifications............................ 251
Primary Filter and Water Separator.......... 317
Running Out of Fuel................................ 262
Secondary Filter and Water Separator/
Heater.................................................. 318
Very Cold Weather Operation................... 256
Water in Fuel........................................... 256Fuel (cont.)
Water in Warning Light............................ 182
What Fuel to Use.................................... 253
Fuses
Fuses and Circuit Breakers...................... 341
Instrument Panel Fuse Block................... 342
Underhood Fuse Block............................. 344
Windshield Wiper..................................... 341
G
Gage
Air Pressure............................................. 183
Check Gages Warning Light..................... 180
Engine Coolant Temperature.................... 173
Filter Minder............................................ 182
Fuel......................................................... 181
Hourmeter................................................ 183
Oil Pressure............................................. 175
Speedometer........................................... 163
Tachometer.............................................. 163
Transmission Temperature........................ 178
Voltmeter Gage........................................ 168
Gasoline
Octane..................................................... 251
Specifications........................................... 251
Gasoline Engine, Starting.............................. 97
GM Mobility Reimbursement Program.......... 407
422