light CHEVROLET C/K 2003 Owner's Guide

2-55
Inter-Axle Differential Lock Control
(If Equipped)
If your vehicle has this
feature, the switch is located
in the center of the
instrument panel.
If you're approaching a slippery surface where it looks
like one or even all of the wheels may start to slip, you
can press the bottom of this switch. It locks your rear
differentials so that power is transmitted equally to both
rear axles.Let up on the accelerator before you turn on your
inter
-axle differential lock. When you turn on this
control, the diff lock indicator on the center of the
instrument panel will light.
NOTICE:
Activating the inter-axle differential lock when
the rear wheels are actually spinning freely, as
they might on ice or snow, can cause you to lose
control of the vehicle. It can also damage the
axles. Turn on this control only when the wheels
are not spinning freely.

2-58
The exterior lamp control has four positions:
OFF: Turning the control to this position turns off all
lamps except the Daytime Running Lamps (DRL).
(Parking Lamps): Turning the control to this
position turns on the parking lamps, together with the
following:

Marker Lamps

Taillamps

License Plate Lamps

Instrument Panel Lights
(Headlamps): Turning the control to this position
turns on the headlamps, together with the previously
listed lamps and lights.
You can switch your headlamps from low to high
beam by pulling the turn signal/multifunction lever
toward you. Pull the lever toward you again to return
to low beam.
A circuit breaker protects your headlamps. If you have
an electrical overload, your headlamps will flicker on
and off. Have your headlamp wiring checked right away
if this ever happens.
Headlamps On Reminder (If Equipped)
If you have this system, a tone will sound when your
headlamps and/or parking lamps are turned on and your
ignition is in LOCK or ACCESSORY.
Daytime Running Lamps
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
DRL can be helpful in many different driving
conditions, but they can be especially helpful in the
short periods after dawn and before sunset. Fully
functional daytime running lamps are required on all
vehicles first sold in Canada.
The DRL system will make your headlamps come
on at reduced brightness when the following conditions
are met:

The ignition is on,

the exterior lamp control is off, and

the parking brake is released.
When the DRL are on, only your headlamps will be on.
The taillamps, sidemarker and other lamps won't be on.
Your instrument panel won't be lit up either.

2-59
When it begins to get dark,
your DRL indicator light is
a reminder to turn the
headlamps on. The other
lamps that come on with
your headlamps, will also
come on.
When you turn the headlamps off, the regular lamps will
go off, and your low
-beam headlamps will change to the
reduced brightness of DRL.
To idle your vehicle with the DRL off, set the parking
brake. The DRL will stay off until you release the
parking brake.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
Marker Lamp Defeat Switch
If your vehicle has this feature, you can manually blink
the marker and clearance lamps.
The marker lamp
defeat switch is located
in the instrument panel
switchbank.
Press and hold the bottom of the switch to turn off
the marker and clearance lamps. When you release
the switch, the marker and clearance lamps will come
back on.

2-60
Interior Lamps
Instrument Panel Brightness Control
This feature controls the brightness of the instrument
panel lights.
The thumbwheel for this feature is located to the right of
the exterior lamp control.
Turn the thumbwheel up to brighten the lights. When the
thumbwheel is moved to the first position, the radio
display and transmission selection display will go to full
intensity. The instrument panel cluster will also be dimly
lit. Moving the thumbwheel up to the next position will
activate the interior dome lamps.
Dome Lamps
The dome lamps will come on when you open a door.
You can also turn the dome lamps on by moving the
thumbwheel, located to the right of the exterior lamp
control, all the way up to the second position. In this
position, the dome lamps will remain on whether a door
is open or closed.
You can use the dome override button to set the dome
lamps to automatically come on when a door is open, or
to remain off.
The dome override button is located below the exterior
lamp control.
If the dome override button is pushed in, the dome
lamps will not come on. Use this feature when you want
to leave your door(s) open for an extended period of
time and do not want to run the battery down.
If the dome override button is in the out position, the
interior lamps will work as usual.

2-61 Illuminated Entry
The delayed illumination feature will allow you to enter
or exit your vehicle with the lights on for about 20
seconds, after the door is closed or the ignition is cycled.
Reading Lamps (If Equipped)
If your vehicle has reading lamps, press the button next
to the lamp to turn the lamp on or off.
Mirrors
Inside Rearview Mirror (If Equipped)
Pull the tab under the mirror toward you to reduce glare
from headlamps behind you after dark. Push the tab
away from you to restore the mirror to the daytime
position.
Outside Rearview Mirrors
Adjust the outside rearview mirrors so you can see a
little of the side of your vehicle, and the area beside
your vehicle from a comfortable driving position. Some
mirrors can be folded in to enter narrow passageways.

2-62
Power Outside Rearview Mirrors (If Equipped)
If you have power outside rearview mirrors, they can be
adjusted from inside the vehicle.
The control for this
feature is located on
the driver's door.
Select the mirror you want to move by turning the
switch clockwise to adjust the passenger's side mirror,
or counterclockwise to adjust the driver's side mirror.
The center position is neutral.
Then, adjust the mirror by pressing the outer arrows on
the switch until the mirror is in the desired position.Heated Outside Rearview Mirrors (If Equipped)
If your vehicle has this feature, your outside rearview
mirrors can be defrosted.The switch is for this
feature is located in the
instrument panel
switchbank.
Press the bottom of the switch to turn the heated outside
rearview mirrors on. The switch indicator light will be
come on and stay on whenever the heated outside
rearview mirrors are activated.
Your rear window defogger will also come on each
time this feature is activated. If your vehicle has a rear
window defogger, See ªRear Window Defoggerº in
the index.

2-65
Ashtrays and Cigarette Lighter
Your vehicle has an ashtray and a cigarette lighter
located in the center floor console. To open the
removeable ashtray, flip open the top.
NOTICE:
If you store paper or other things that burn in your
ashtrays, they could be set on fire by cigarettes or
other smoking materials. That could cause a fire
and possibly damage your vehicle. Do not store
papers and other things that burn in your ashtrays.
To use the cigarette lighter, push it in all the way and let
it go. When it's ready, it will pop back out by itself.
NOTICE:
Holding a cigarette lighter in with your hand
while it's heating can make it overload, damaging
the lighter and the heating element. Just push the
lighter all the way in and let it go. When it's
done, it will pop back out by itself.
Sun Visors
To block out glare, you can swing down the visors. You
can also swing them out to block glare from the side.
Accessory Power Outlets
With accessory power outlets, you can plug in
auxiliary electrical equipment such as a cellular
telephone or CB radio.
The accessory power outlets are 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.
These circuits are protected by a fuse and have
maximum current levels.
NOTICE:
When using the accessory power outlets,
maximum load of any electrical equipment
should not exceed 14 amps. Be sure to turn off
any electrical equipment when not in use.
Leaving electrical equipment on for extended
periods can drain the battery.

2-67
The eight-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: CHMSL

Red: Battery Feed

Dark Blue: Trailer Brake
Trailer Connections (C6/C7/C8
Models Only) (If Equipped)
If your vehicle has these trailer connections, they are
located at the rear of the cab for a tractor and at the rear
of the chassis when towing a trailer. There will be an air
connection and an electrical connection.
Be sure that the couplings to the trailer are
made correctly.
Air Connections
If you are not connecting the trailer air line connections
to another piece of equipment, be sure to replace their
protective caps.
Electrical Connections
This system is a seven-wire cable that will connect to
the trailer, supplying power to the trailer's lighting
system. When not in use, it is stored in the trailer
air
-hose storage bracket.
NOTICE:
Starting in 1998, the center pin (also known as
the auxiliary circuit) of the seven
-pin trailer
electrical connector will be wired to provide
continuous power for the trailer anti
-lock brake
systems when the ignition key is in the on
position. Care should be taken to insure that
continuous power on this circuit will not cause
damage to the trailer electrical system.
Consult with the trailer manufacturer for the
proper operation and checking procedures for
the trailer anti
-lock brake systems.

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The main components of your instrument panel are the following:
A. Vents
B. Instrument Panel Cluster
C. Column Shift Lever (If Equipped)
D. Air Brake Control(s) (If Equipped)
E. Auxiliary Gages (If Equipped)
F. Exterior Lamp Control
G. Turn Signal Multifunction Lever
H. Hazard Warning Flashers ButtonI. Auxiliary Switches (If Equipped)
J. Audio System or Storage Area
K. Auxiliary Warning Lights
L. Comfort Controls
M. Instrument Panel Switchbank
N. Air Bag Off Switch (If Equipped)
P. Accessory Power Outlets

2-73 Tachometer
7.2L Caterpillar
Diesel Engine and
7.8L DURAMAX
Diesel EnginesGasoline and
6.6L DURAMAX
Diesel Engines
This gage shows the engine speed in revolutions per
minute (rpm).
Warning Lights, Gages and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause an
expensive repair or replacement. Paying attention to
your warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle's functions. As you
will see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they're working. If you are
familiar with this section, you should not be alarmed
when this happens.