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Instrument Panel Overview........................ 140
Hazard Warning Flashers.......................... 142
Other Warning Devices............................. 142
Horn.......................................................... 142
Tilt Wheel.................................................. 142
Turn Signal/Multifunction Lever.................. 143
Turn and Lane-Change Signals................. 144
Headlamp High/Low-Beam Changer.......... 144
Windshield Wipers..................................... 145
Windshield Washer.................................... 146
Cruise Control........................................... 146
Exterior Lamps.......................................... 150
Headlamps on Reminder........................... 150
Daytime Running Lamps (DRL)................. 151
Marker Lamps........................................... 152
Instrument Panel Brightness...................... 152
Dome Lamps............................................. 153
Entry Lighting............................................ 154
Reading Lamps......................................... 154
Instrument Panel Switchbank..................... 154
Accessory Power Outlet(s)........................ 156
Ashtray(s) and Cigarette Lighter................ 157Climate Controls......................................... 157
Climate Control System............................. 157
Outlet Adjustment...................................... 160
Rear Heating System................................ 161
Warning Lights, Gages, and Indicators..... 161
Instrument Panel Cluster........................... 162
Speedometer and Odometer...................... 163
Trip Odometer........................................... 163
Tachometer............................................... 163
Engine Speed Limiter................................ 164
Safety Belt Reminder Light........................ 164
Safety Belt Reminder Tone....................... 164
Airbag Readiness Light............................. 165
Airbag Off Light......................................... 166
Charging System Light.............................. 167
Voltmeter Gage......................................... 168
Service Transmission Warning Light.......... 168
Range Inhibit Warning Indicator................. 169
Brake System Warning Light..................... 169
Anti-Lock Brake System Warning Light...... 172
Trailer Anti-Lock Brake System
Warning Light........................................ 172
Section 3 Instrument Panel
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Hazard Warning Flashers
The hazard warning flashers warn others. They
also let police know you have a problem.
Your front and rear turn signal lamps will flash
on and off.
The hazard warning
flasher button is located
on top of the steering
column.
The hazard warning flashers work no matter what
ignition position the key is in, and even if the
key is not in the ignition.
Press the button to make the front and rear turn
signal lamps flash on and off. Press the button
again to turn the flashers off.
When the hazard warning flashers are on, your
turn signals will not work.
Other Warning Devices
If you carry reflective triangles, you can set them up
at the side of the road about 300 feet (100 m)
behind your vehicle.
Horn
Sound the horn by pushing the center of the
steering wheel. If you have the optional air horn, it is
controlled by a cord that you will find up above and
to the left of the driver. The harder you pull on the
cord, the louder the air horn will sound. The air horn
works only after your air brake system pressure
gets up to about 115 psi (790 kPa). The air horn will
work properly unless the air brake system pressure
drops below 60 psi (415 kPa).
Tilt Wheel
A tilt wheel allows you to adjust the steering wheel
before you drive. You can raise it to the highest
level to give your legs more room when you
exit and enter the vehicle.
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Page 301 of 430

Electric Air Compressor
Your vehicle may have an electric air compressor.
This compressor is used to run options that
require pressurized air, such as an air horn, air
seat, 7.8L engine exhaust restrictor, or 7.8L engine
exhaust brake.
The air compressor is used when vehicles do not
have an air brake system.
The air supply for
this system must be
maintained by releasing
the drain valve to eject
any moisture that
may have built up in
the system.
It is recommended that this system be drained on
a weekly basis.
Clutch Pedal Free Travel
If you have a V8 engine and a manual
transmission, the clutch will need adjustment
when pedal free travel gets down to about 1/4 inch
(6 mm), as measured at the clutch pedal pad.
You should have 1 1/2 to 2 inches (38 to 51 mm)
of clutch pedal free travel.
If the clutch ever needs service, be sure to use
only GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the
required chassis lubrication intervals and identifies
proper lubricants to use. Be sure to see the
Maintenance Schedule before performing any
chassis lubrication service. To determine location of
chassis lubrication items, use the following charts.
301
Page 345 of 430
Fuse Usage
RR DEFOG Rear Defogger
ENG 1 Engine 1
ENG 3 Engine 3
PCM-B Powertrain Control Module
Fuse Usage
BLANK Not Used
ENG 4 Engine 4
ENG 2 Engine 2
HTD FUEL Heated Fuel
BLANK Not Used
BLANK Not Used
02A Emissions
A/C COMP Air Conditioning Compressor
ABS 1 Anti-lock Brake System 1
ABS 2 Anti-lock Brake System 2
ABS 3 Anti-lock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN Horn
NOTE 2L18 Fuel, LG4 Powertrain Control
Valve, LG5 Electronic Control
Module Primary Underhood Fuse Block
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Fuse Usage
NOTE 3L18 Fuel, LG4 Powertrain Control
Valve, LG5 Electronic Control
Module
STUD A Spare
STUD B Spare
Relay Usage
NOTE 1LLY/L18 Fuel Pump Relay, LG4/LG5
Heated Fuel Relay
IGN B Ignition Relay
STARTER Starter Relay
HORN Horn Relay
IGN A Ignition Relay
PTO/ECU*Power Take-Off/Engine Control Unit
(*Diesel 7.8L LG4)
REVERSE Reverse Relay
NEUTRAL
STARTNeutral Start (LG4 Allison Automatic
Transmission Series 3000/3500)
Fuse Usage
IGN 1 Ignition 1
IGN 4 Ignition 4
IGN 3 Ignition 3
BATT/HAZ Battery/Hazard Warning Flashers
HEADLAMP Headlamps
LIGHTING Interior/Exterior Lamps
HVAC Climate Control System
NOTEC4/C5 Electric Brake,
C6/C7/C8 Brake Lamps Secondary Underhood
Fuse Block
346
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H
Hazard Warning Flashers............................ 142
Headlamp Wiring......................................... 341
Headlamps
Bulb Replacement.................................... 315
Daytime Running Lamps.......................... 151
High/Low Beam Changer......................... 144
On Reminder........................................... 150
Heater......................................................... 157
High Idle System......................................... 106
Highbeam On Light..................................... 179
Highway Hypnosis....................................... 229
Hill and Mountain Roads............................. 230
Hood
Checking Things Under............................ 266
Latches.................................................... 267
Horn............................................................ 142
Hourmeter Gage.......................................... 183
How to Use This Manual................................ 4
How to Wear Safety Belts Properly............... 26
Hydraulic Brake Systems............................. 211
I
Ignition Positions........................................... 96
Infants and Young Children, Restraints .......... 45
Inflation - Tire Pressure............................... 322
Instrument Panel
Overview.................................................. 140
Switchbank.............................................. 154
Instrument Panel (I/P)
Brightness................................................ 152
Cluster..................................................... 162
J
Jump Starting.............................................. 305
K
Keyless Entry System................................... 87
Keys............................................................. 86
423