GMC SIERRA 1999 Owner's Manual

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If you are stopped by heavy snow, you could be in a
serious situation. You should probably stay with your
vehicle unless you know for sure that you are near help
and you can hike through the snow. Here are some
things to do to summon help and keep yourself and your
passengers safe:

Turn on your hazard flashers.

Tie a red cloth to your vehicle to alert police that
you've been stopped by the snow.

Put on extra clothing or wrap a blanket around you.
If you have no blankets or extra clothing, make body
insulators from newspapers, burlap bags, rags, floor
mats
-- anything you can wrap around yourself or
tuck under your clothing to keep warm.
You can run the engine to keep warm, but be careful.

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CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill
you. You can't see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn't collect there.
Open a window just a little on the side of the
vehicle that's away from the wind. This will help
keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly. This
uses less fuel for the heat that you get and it keeps the
battery (or batteries) charged. You will need a
well
-charged battery (or batteries) to restart the vehicle,
and possibly for signaling later on with your headlamps.
Let the heater run for a while.
If you have a diesel engine, you may have to run it at a
higher speed to get enough heat. Then, shut the engine
off and close the window almost all the way to preserve
the heat. Start the engine again and repeat this only
when you feel really uncomfortable from the cold. But
do it as little as possible. Preserve the fuel as long as you
can. To help keep warm, you can get out of the vehicle
and do some fairly vigorous exercises every half hour or
so until help comes.

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Recreational Vehicle Towing
There may be times when you want to tow your vehicle
behind another vehicle for use at your destination. Be
sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
Two-Wheel-Drive Vehicles
Tw o-wheel-drive vehicles should not be towed with
all four wheels on the ground. Two
-wheel-drive
transmissions have no provisions for internal lubrication
while being towed. To properly tow these vehicles, they
should be placed on a platform trailer with all four
wheels off the ground.
In rare cases when it's unavoidable that a
two
-wheel-drive vehicle is to be towed with all four
wheels on the ground, the propeller shaft to axle yoke
orientation should be marked and the propeller shaft
removed following the applicable service manual
removal/installation procedure.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmission fluid level before driving the truck.

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CAUTION:
Shifting the transfer case into NEUTRAL (N) can
cause your vehicle to roll even if the transmission
is in PARK (P), for an automatic transmission, or
if your vehicle is in gear, for a manual
transmission. You or others could be injured.
Make sure the parking brake is firmly set before
you shift the transfer case into NEUTRAL (N).
Vehicles equipped with the electronic transfer case
cannot be towed with all four wheels on the ground.
Use the following procedure to correctly tow your
vehicle on all four wheels with a manual transfer case:
1. Firmly set the parking brake.
2. Place the transmission in PARK (P) or a manual
transmission in FIRST (1).
3. Securely attach the vehicle being towed to the
tow vehicle.
4. With the engine running, shift the transfer case to
NEUTRAL (N). See ªFour
-Wheel Driveº in the
Index for the proper procedure to select the neutral
position for your vehicle.
5. Release the parking brake only after the vehicle
being towed is firmly attached to the towing vehicle.
6. Turn the ignition to OFF. The OFF position unlocks
the steering column and reduces battery drain.
Unlocking the steering column will allow the proper
movement of the front wheels and tires during towing.

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Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door or in the Incomplete Vehicle Document
in the cab.
The label shows the size of your original tires and the
inflation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the GVWR
(Gross Vehicle Weight Rating). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads on
your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should spread
it out.
CAUTION:
In the case of a sudden stop or collision, things
carried in the bed of your truck could shift
forward and come into the passenger area,
injuring you and others. If you put things in the
bed of your truck, you should make sure they are
properly secured.

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Using heavier suspension components to get added
durability might not change your weight ratings. Ask
your dealer to help you load your vehicle the right way.
NOTICE:
Some vehicles may be equipped with RPO VYU
(snow plow prep package). With this option, the
payload your vehicle can carry is reduced when a
snow plow is installed. Your vehicle can be
damaged if either the front or rear axle ratings,
or the GVW are exceeded.
As a general guideline, with a 650 lb. (295 kg)
snow plow, the weight of the occupants and cargo
must not exceed 300 lb. (135 kg). However, this
may depend on the vehicle's option content.
Therefore, to help avoid vehicle damage:

Make sure the weight on the front andrear
axles does not exceed their respective
axle ratings.
NOTICE: (Continued)
NOTICE: (Continued)

For the front axle, if more cargo or
passengers need to be carried, appropriate
counter ballast must be installed rear of the
rear axle and properly secured.

Total vehicle weight must not exceed the
GVW rating.

See your dealer for advice and information
about using a snow plow on your vehicle.
CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose control
and crash. Also, overloading can shorten the life
of your vehicle.

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NOTICE:
Your warranty does not cover parts or
components that fail because of overloading.
If you put things inside your vehicle -- like suitcases,
tools, packages, or anything else
-- they go as fast as the
vehicle goes. If you have to stop or turn quickly, or if
there is a crash, they'll keep going.
CAUTION:
Things you put inside your vehicle can strike and
injure people in a sudden stop or turn, or in a crash.

Put things in the cargo area of your vehicle.
Try to spread the weight evenly.

Never stack heavier things, like suitcases,
inside the vehicle so that some of them are
above the tops of the seats.

Don't leave an unsecured child restraint in
your vehicle.
CAUTION: (Continued)
CAUTION: (Continued)

When you carry something inside the
vehicle, secure it whenever you can.

Don't leave a seat folded down unless you
need to.
There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle for
Off
-Road Drivingº in the Index.
Truck-Camper Loading Information
The Truck-Camper Loading label is located inside your
glove box. It will tell you if your vehicle can carry a
slide
-in camper, how much of a load your vehicle can
carry, and how to correctly spread out your load.
Also, it will help you match the right slide
-in camper
to your vehicle.
When you carry a slide
-in camper, the total cargo load
of your vehicle is the weight of the camper, plus

everything else added to the camper after it left
the factory,

everything in the camper and

all the people inside.

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The Cargo Weight Rating (CWR) is the maximum
weight of the load your vehicle can carry. It doesn't
include the weight of the people inside. But, you can
figure about 150 lbs. (68 kg) for each seating position.
The total cargo load must not be more than your
vehicle's CWR.
Refer to the Truck
-Camper Loading Information label in
glove box for dimensions A and B as shown in the
following illustration.
Use the rear edge of the load floor for measurement
purposes. The recommended location for the cargo center
of gravity is at point C for the CWR. It is the point where
the mass of a body is concentrated and, if suspended at
that point, would balance the front and rear.Here is an example of proper truck and camper match:
A. Camper Center of Gravity
B. Recommended Center of Gravity Location Zone
The camper's center of gravity should fall within the
center of gravity zone for your vehicle's cargo load.
You must weigh any accessories or other equipment that
you add to your vehicle. Then, subtract this extra weight
from the CWR. This extra weight may shorten the
center of gravity zone of your vehicle. Your dealer can
help you with this.

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If your slide-in camper and its load weighs less than the
CWR, the center of gravity zone for your vehicle may
be larger.
Your dealer can help you make a good vehicle
-camper
match. He'll also help you determine your CWR.
After you've loaded your vehicle and camper, drive to a
weigh station and weigh the front and rear wheels
separately. This will tell you the loads on your axles.
The loads on the front and rear axles shouldn't be more
than either of the GAWRs. The total of the axle loads
should not be more than the GVWR.
Open your driver's door and look at the Certification/Tire
label to find out your GAWR and GVWR.
If you've gone over your weight ratings, move or take
out some things until all the weight falls below the
ratings. Of course, you should always tie down any
loose items when you load your vehicle or camper.
When you install and load your slide
-in camper, check
the manufacturer's instructions.
If you want more information on curb weights, cargo
weights, Cargo Weight Rating and the correct center of
gravity zone for your vehicle, your dealer can help you.
Just ask for a copy of ªConsumer Information,
Truck
-Camper Loading.º
Trailer Recommendations
You must subtract your hitch loads from the CWR for
your vehicle. Weigh your vehicle with the trailer attached,
so that you won't go over the GVWR or GAWR.
You'll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, see ªTrailer Towingº in
the Index.

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Camper Wiring Harness
(If Equipped)
A five-wire harness may be stored under your vehicle.
The harness is located inside the frame rail and is even
with the front of the pickup box. This harness has a
30 amp battery feed wire and no connector, and should be
wired by a qualified electrical technician. After choosing
an aftermarket mating connector pair, have the technician
attach one connector to the five
-wire camper harness and
the other connector to the wiring harness for the camper.
The technician can use the following color code chart
when connecting the wiring harness to your camper.
Brown: Rear Lamps

Yellow: Left Stoplamp and Turn Signal

Dark Green: Right Stoplamp and Turn Signal

White (Heavy Gage): Ground

Light Green: Back
-up Lamps
When the harness is not being used, store it in its
original place. Wrap the harness together and tie it
neatly so it won't be damaged.
Pickup Conversion to Chassis Cab
General Motors is aware that some vehicle owners may
consider having the pickup box removed and a
commercial or recreational body installed. Before you
do so, first contact the GM Customer Assistance Office
for your area for information on such conversions
specific to this vehicle. (See the ªWarranty and Owner
Assistanceº booklet for Customer Assistance Office.)
Owners should be aware that, as manufactured, there are
differences between a chassis cab and a pickup with the
box removed which may affect vehicle safety. The
components necessary to adapt a pickup to permit its
safe use with a specialized body should be installed by a
body builder in accordance with the information
available from the Customer Assistance Office.