ignition CHEVROLET C/K 2003 Owner's Manual

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.

2-71 Speedometer and Odometer
Your speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has been
driven, in either miles (used in the United States) or
kilometers (used in Canada).Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
While the engine is running, press the reset button,
located to the right of the trip odometer, to toggle
between the trip odometer and the regular odometer.
Holding the reset button for two seconds while the
engine is running and the trip odometer is displayed,
will reset it.
To display the odometer reading with the ignition off,
press the reset button.

2-75 Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the airbag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem. The
system check includes the air bag sensors, the air bag
modules, the wiring, the passenger air bag suppression
circuit and the crash sensing and diagnostic module. For
more information on the air bag system, see ªAir Bagº
in the Index.
This light will come on
when you start your vehicle,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.
CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inflate in a crash, or they
could even inflate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN or
START. If the light doesn't come on then, have it fixed
so it will be ready to warn you if there is a problem.

2-78 Charging System Indicator Light
The charging system
indicator light may be
located in the instrument
panel cluster, or with the
auxiliary warning lights
in the center of the
instrument panel.
It should come on briefly when you turn on the ignition,
before the engine is running, as a check to show that it
is working.
If it stays on, or comes on while you are driving, have it
checked right away. You could have a loose generator
drive belt or some other problem.
Driving while this light is on will drain your battery. If
you must drive a short distance with the light on, turn
off your radio and other accessories.
Sustained driving with a generator failure could result in
a lack of back
-up braking if the engine quits or the
power steering pump should fail.
Voltmeter
When your engine is
running, the voltmeter
gage, at the right side of
the instrument panel cluster,
shows the charging
system voltage.
Readings in either warning zone indicate a possible
problem in the electrical system.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in the
vehicle and the engine is left at an idle for an extended
period. This condition is normal since the charging
system may not be able to provide full power at engine
idle. As engine speeds are increased, this condition
should correct itself because higher engine speeds allow
the charging system to create maximum power.
You can only drive a short time on the battery. Be sure
to shut off the radio, the fan or any unnecessary
accessories and have the system serviced.

2-83 Parking Brake Indicator Light
Your vehicle has a brake
indicator light. When the
ignition is on, this light will
come on when you set your
parking brake. The light
will stay on if your parking
brake doesn't release fully.
This light should also come on when you turn the
ignition key to START. If it doesn't come on then, have
it fixed so it will be ready to remind you if the parking
brake is applied or hasn't released fully.
Anti-Lock Brake System Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and it may stay
on for several seconds.
That's normal.
If the light stays on, or comes on when you're driving,
your vehicle needs service. If the BRAKE or LOW AIR
warning light isn't on, you still have brakes, but you
don't have the anti
-lock brake feature. If the BRAKE
and/or LOW AIR warning light is on, you don't have
anti
-lock brakes and there's a problem with your regular
brakes. See ªBrake System Warning Lightº earlier in
this section.
The anti
-lock brake system warning light should come
on briefly when you start the engine. If the light doesn't
come on then, have it fixed so it will be ready to warn
you if there is a problem.

2-84 Trailer Anti-Lock Brake System
Warning Light
If your vehicle is connected
to an anti
-lock brake system
equipped trailer, this light
should come on briefly, as
a check, when you turn on
the ignition.
When this light comes on and stays on, it means there is
something wrong in the trailer anti
-lock brake system.
Have the system repaired immediately.
If an anti
-lock brake system equipped trailer is not
connected, this light is not functional.
Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine
coolant might have overheated and your engine may be
too hot. You should pull off the road, stop your vehicle
and turn off the engine as soon as possible.
See ªEngine Overheatingº in the Index. If you have a
Caterpillar

diesel engine, also see your Caterpillar

Operation & Maintenance Manual.

2-85 Low Coolant Warning Light
You have a low coolant
warning light. If this light
comes on, your system is
low on coolant and the
engine may overheat.
The warning light should come on briefly, as a check,
when you turn on the ignition.
When it comes on, you will also hear a warning tone at
several beats per second for 10 seconds. See ªEngine
Coolantº in the Index and have your vehicle serviced as
soon as you can.
This light may also come on if your vehicle is equipped
with the automatic engine shutdown system and engine
shutdown has begun. See ªEngine Automatic
Shutdownº in the Index.
Wait to Start Indicator (If Equipped)
This light in the center of
the instrument panel will
come on when the intake
heater is on and the ignition
key is in RUN.
Wait until the indicator light turn off before turning the
ignition key to START. See ªEngine Startingº in your
Caterpillar

Operation & Maintenance Manual for more
information.

2-86 Malfunction Indicator Lamp
(Service Engine Soon Light)
If this light comes on
or flashes while you
are driving, two things
may happen.
First, you won't notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may stall
without warning. If either of these things happen, drive
or tow your vehicle to your dealer for service.This light should come on when the ignition is on, but
the engine is not running, as a check to show you it is
working. If it does not come on at all, have it repaired.
NOTICE:
If you keep driving your vehicle with this light
on, after a while, your emission controls may not
work as well, your fuel economy may not be as
good and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.

2-90 Engine Shutdown Warning Light
(If Equipped)
If your vehicle has the
engine shutdown feature,
this light will come on when
engine shutdown is active.
For more information, see ªEngine Alarm and
Automatic Shutdownº in the Index.
Transmission Temperature Gage
(If Equipped)
If you have an automatic
transmission, this gage is
located above the
switchbank in the center of
the instrument panel.
When your ignition is on, the gage shows the
temperature of the transmission oil. A reading in the
warning zone, the red area beginning at 300
F (150
C),
means you must stop driving and check into the cause.
One possible cause is a low oil level in the transmission.
NOTICE:
If you drive when the transmission temperature
gage is in the warning zone, you can badly
damage the transmission.

2-93 Fuel Gage
Your fuel gage is located on
the right side of your
instrument panel cluster.
When the ignition is on, your fuel gage lets you know
about how much fuel you have left. When the gage first
shows empty, you'll still have a little fuel left, but you
should get more fuel soon.
If your vehicle has dual fuel tanks, the reading on the
gage is the total fuel left in both tanks.
Here are four concerns of some operators. None of these
shows a problem with your fuel gage:

The gage moves a little when you turn a corner or
speed up.
The gage doesn't go back to empty when you turn
off the ignition.

At the gas station, the pump shuts off before the gage
reads full.

It takes a little more or less fuel to fill up than the
gage indicated.
If you have a diesel engine, also see your Caterpillar

Operation & Maintenance Manual.
Water in Fuel Warning Light (If Equipped)
If your vehicle is equipped
with a diesel engine, you
may have this light
This light will come on to warn you that there is water
in the fuel system. For more information on how this
light works, see ªDiesel Fuel Requirements and Fuel
Systemº in the Index.