key GMC C-SERIES 1999 User Guide

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2-49
Trailer Connections (If Equipped)
These connections are located at the rear of the
cab. There is an air connection and a trailer
electrical connection.
Be sure that the couplings to the trailer are
made correctly.
Air Connections
The red line is the supply
line. It provides emergency
or constant air pressure. The
blue line is the control line,
providing service air.
Electrical Connections (If Equipped)
If your vehicle has this system, it has a seven-wire cable
that will go to the trailer to supply electrical 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 7
-pin trailer electrical
connector will be wired to provide continuous
power for the trailer anti
-lock brake systems
when the ignition key is in ON or RUN. 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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2-55
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.
Gages can indicate when there may be or is a problem
with one of your vehicle's functions. Often gages and
warning lights work together to let you know when
there's a problem with your vehicle.When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual's advice.
Waiting to do repairs can be costly
-- and even
dangerous. So please get to know your warning lights
and gages. They're a big help.
Safety Belt Reminder Light (Option)
When the key is turned to
RUN or START, a light will
come on for about eight
seconds to remind people
to fasten their safety belts.
Safety Belt Reminder Tone (Option)
When the key is turned to RUN or START, a tone will
sound for about eight seconds to remind people to fasten
their safety belts.
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2-60 Apply Park Brake Warning Light (Option)
This light warns the driver
that the ignition has been
turned off without applying
the parking brake. The
warning light should come
on, as a check, when you
start the engine.
When it comes on, you will also hear a warning tone.
Leaving the vehicle in this condition could result in your
vehicle moving and will discharge the battery.
Parking Brake Warning Light
This light turns on as a
check when the engine is
first started and any time the
system needs adjustment or
there is a malfunction in the
electric/hydraulic parking
brake system.
When the SERVICE PARK BRAKE light comes on,
you will also hear a warning tone. If this light comes on,
have the system repaired immediately.
CAUTION:
If the SERVICE PARK BRAKE warning light
comes on and the warning tone sounds, your
vehicle can stop suddenly and without further
warning. You or others could be injured. If the
SERVICE PARK BRAKE warning light and the
warning tone come on, pull over to the side of the
road and apply the parking brake immediately.
Parking Brake Indicator Light
Vehicles with hydraulic or
air brakes have a parking
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.
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2-61 Anti-Lock Brake System Warning Light
(Option)
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 PRIMARY 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
PRIMARY 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 turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
Engine Coolant Temperature Gage
Gasoline Engine Diesel Engine
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.
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2-63 Intake Heater Indicator Light
(Diesel Engines)
This light on the instrument
panel will come on when
the intake heater is on and
the ignition key is in ON.
Since the light is illuminated whenever the intake heater
is activated, it is normal for the light to cycle on and off
as the heater cycles during engine warm
-up. See
ªEngine Startingº in your Caterpillar
Operation &
Maintenance Manual for more information.
Diff Lock Indicator Light (If Equipped)
This light on the instrument
panel is on when the
inter
-axle differential lock
system is in use.
The light will come on momentarily during starting.
If the light fails to come on, have it repaired as soon as
possible so you will be aware when the lock system is
in use.
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4-3
Drunken Driving
Death and injury associated with drinking and driving is
a national tragedy. It's the number one contributor to
the highway death toll, claiming thousands of victims
every year.
Alcohol affects four things that anyone needs to drive
a vehicle:

Judgment

Muscular Coordination

Vision

Attentiveness.
Police records show that almost half of all motor
vehicle
-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was drinking
and driving. In recent years, over 17,000 annual motor
vehicle
-related deaths have been associated with the use
of alcohol, with more than 300,000 people injured.
Many adults
-- by some estimates, nearly half the adult
population
-- choose never to drink alcohol, so they
never drive after drinking. For persons under 21, it's
against the law in every U.S. state to drink alcohol.
There are good medical, psychological and
developmental reasons for these laws.The obvious way to solve the leading highway safety
problem is for people never to drink alcohol and then
drive. But what if people do? How much is ªtoo muchº
if the driver plans to drive? It's a lot less than many
might think. Although it depends on each person and
situation, here is some general information on
the problem.
The Blood Alcohol Concentration (BAC) of someone
who is drinking depends upon four things:

The amount of alcohol consumed

The drinker's body weight

The amount of food that is consumed before and
during drinking

The length of time it has taken the drinker to
consume the alcohol.
According to the American Medical Association, a
180
-lb. (82 kg) person who drinks three 12-ounce
(355 ml) bottles of beer in an hour will end up with a
BAC of about 0.06 percent. The person would reach the
same BAC by drinking three 4
-ounce (120 ml) glasses
of wine or three mixed drinks if each had 1
-1/2 ounces
(45 ml) of a liquor like whiskey, gin or vodka.
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5-2
Hazard Warning Flashers
Your hazard warning flashers let you 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 flasher switch is located on the
steering column.
Press the button in to make your front and rear turn
signal lamps flash on and off.
Your hazard warning flashers work no matter what
position your key is in, and even if the key isn't in.
To turn off the flashers, pull out on the collar. When
the hazard warning flashers are on, your turn signals
won't work.
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5-3 Hazard Warning Flasher Switch
(If Equipped)
With some options, such as U86-trailer wiring or
RQ3
-tractor application, you will have this switch.
This switch replaces the hazard switch mounted on the
steering column. It is mounted in the instrument panel,
usually to the left of and below the steering column.
Pull the switch out to make your front and rear turn
signal lamps flash on and off. A light next to the switch
will also flash. Push it back in to turn off the flashers.
The turn signal lamps won't flash if you're braking.
This switch works no matter what position the key is in,
and even if the key isn't in the ignition.
When the hazard warning flashers are on, your turn
signals won't work.
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5-4 Signal-Stat Turn Signal and Hazard
Warning Flasher (If Equipped)
If you have this system, it lets you warn others. It also
lets police know you have a problem. It makes your
front and rear turn signal lamps flash on and off, but
they won't flash if you're braking.
The switch is on the end of the signal
-stat housing.
To make it work, pull out on the hazard lever until it
locks into place. It works no matter what position your
key is in, and even if the key isn't in.
To turn off the flasher, move
the turn signal lever either
up or down. Then move the
signal lever back to the
center position.
When the hazard warning flashers are on, your turn
signals won't work.
Other Warning Devices
If you carry reflective triangles, you can set one up at
the side of the road behind your vehicle in the
recommended manner per FMCSR (Federal Motor
Carrier Safety Regulation) Section 392.22, to
warn others.
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6-16 Engine Oil Additives
Don't add anything to your oil. Your dealer is ready to
advise if you think something should be added.
When to Change Engine Oil
Your vehicle has a computer that lets you know when to
change your engine oil. This is not based on mileage,
but on engine revolutions and engine operating
temperature. When the computer has calculated that the
oil needs changing, the Oil Life Monitor will indicate
that a change is necessary. The mileage between oil
changes will vary depending on how you drive your
vehicle
-- usually between 3,000 miles (5 000 km) and
7,500 miles (12 500 km) since your last oil change.
Under severe conditions, the indicator may come on
before 3,000 miles (5 000 km). Never drive your vehicle
more than 7,500 miles (12 500 km) or 12 months
(whichever occurs first) without an oil change.
The system won't detect dust in the oil. So, if you
drive in a dusty area, be sure to change your oil every
3,000 miles (5 000 km) or sooner. Remember to reset
the CHANGE OIL light whenever the oil is changed.How to Reset the Oil Life Monitor
To reset the CHANGE OIL message, turn the ignition
key to RUN with the engine off. Fully press and release
the accelerator pedal three times within 10 seconds. If
the CHANGE OIL message flashes for five seconds, the
system is reset. If the message does not display for five
seconds, you will need to reset the system again.
What to Do with Used Oil
Did you know that used engine oil contains certain
elements that may be unhealthy for your skin and could
even cause cancer? Don't let used oil stay on your skin
for very long. Clean your skin and nails with soap and
water, or a good hand cleaner. Wash or properly throw
away clothing or rags containing used engine oil. (See
the manufacturer's warnings about the use and disposal
of oil products.)
Used oil can be a real threat to the environment. If you
change your own oil, be sure to drain all free
-flowing oil
from the filter before disposal. Don't ever dispose of oil
by putting it in the trash, pouring it on the ground, into
sewers, or into streams or bodies of water. Instead,
recycle it by taking it to a place that collects used oil. If
you have a problem properly disposing of your used oil,
ask your dealer, a service station or a local recycling
center for help.
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