1999 GMC YUKON light

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Freeway Driving
Mile for mile, freeways (also called thruways, parkways,
expressways, turnpikes or superhighways) are the safest
of all roads. But they have their own special rules.
The most important advice on freeway driving is: Keep
up with traffic and keep to the right. Drive at the same
speed most of the other drivers are driving. Too
-fast or
too
-slow driving breaks a smooth traffic flow. Treat the
left lane on a freeway as a passing lane.At the entrance, there is usually a ramp that leads to the
freeway. If you have a clear view of the freeway as you
drive along the entrance ramp, you should begin to
check traffic. Try to determine where you expect to
blend with the flow. Try to merge into the gap at close to
the prevailing speed. Switch on your turn signal, check
your mirrors and glance over your shoulder as often as
necessary. Try to blend smoothly with the traffic flow.
Once you are on the freeway, adjust your speed to the
posted limit or to the prevailing rate if it's slower. Stay
in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before you leave the lane, glance quickly over your
shoulder to make sure there isn't another vehicle in your
ªblindº spot.
Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to move
slightly slower at night.
When you want to leave the freeway, move to the proper
lane well in advance. If you miss your exit, do not,
under any circumstances, stop and back up. Drive on to
the next exit.
The exit ramp can be curved, sometimes quite sharply.

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Winter Driving
Here are some tips for winter driving:

Have your vehicle in good shape for winter.

You may want to put winter emergency supplies in
your vehicle.Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Driving on Snow or Ice
Most of the time, those places where your tires meet the
road probably have good traction.
However, if there is snow or ice between your tires and
the road, you can have a very slippery situation. You'll
have a lot less traction or ªgripº and will need to be
very 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 charged. You will need a well
-charged battery to
restart the vehicle, and possibly for signaling later on
with your headlamps. Let the heater run for a while.
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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4-53 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

Start your engine;

Shift into a gear; and

Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake adjustment. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Light-Duty Wiring Harness

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Additional Heavy-Duty Wiring
An eight
-wire harness is stored under the rear bumper of
your vehicle. The five
-wire light-duty harness is located
at the left hand rear inner lower quarter panel. The
additional heavy
-duty wiring is located forward of the
rear bumper and is attached to the center of the rear
crossmember or the forward vertical surface of the
platform hitch.
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 tothe eight
-wire trailer harness and the other connector to the
wiring harness on the trailer. Be sure that the wiring
harness on the trailer is strapped to the trailer's frame and
leave it loose enough so that the wiring doesn't bend or
break, but not so loose that it drags on the ground. The
technician can use the following color code chart when
connecting the wiring harness to your trailer.

Brown: Rear Lamps

Yellow: Left Stoplamp and Turn Signal

Dark Green: Right Stoplamp and Turn Signal

White (Heavy Gauge): Ground

Light Green: Back
-up Lamps

White (Light Gauge): Center High
-Mounted Stop
Lamp (If Equipped)

Blue: Auxiliary/Electric Trailer Brake Circuit
(If Equipped)

Orange: Fused Auxiliary Circuit (If Equipped)
Store the harness in its original place. Wrap the harness
together and tie it neatly so it won't be damaged.

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Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. But please use the following steps to do
it safely.
CAUTION:
Batteries can hurt you. They can be dangerous
because:

They contain acid that can burn you.

They contain gas that can explode or ignite.

They contain enough electricity to
burn you.
If you don't follow these steps exactly, some or all
of these things can hurt you.
NOTICE:
Ignoring these steps could result in costly damage
to your vehicle that wouldn't be covered by
your warranty.
The ACDelco Freedom battery in your vehicle
has a built-in hydrometer. Do not charge, test or
jump start the battery if the hydrometer looks
clear or light yellow. Replace the battery when
there is a clear or light yellow hydrometer and a
cranking complaint.
Trying to start your vehicle by pushing or pulling
it won't work, and it could damage your vehicle.

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1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
NOTICE:
If the other system isn't a 12-volt system with a
negative ground, both vehicles can be damaged.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL (N) before setting the parking brake.
Be sure the transfer case is not in NEUTRAL (N).3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off all lamps
that aren't needed as well as radios. This will avoid
sparks and help save both batteries. And it could
save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.

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4. Open the hoods and locate the batteries. Find the
positive (+) and negative (
-) terminals on
each battery.
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You don't
need to add water to the ACDelco Freedom

battery installed in every new GM vehicle. But if
a battery has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take care
of that first. If you don't, explosive gas could
be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged, too.
Before you connect the cables, here are some basic
things you should know. Positive (+) will go to
positive (+) and negative (
-) will go to a heavy
unpainted metal engine part. Don't connect
positive (+) to negative (
-) or you'll get a short
that would damage the battery and maybe other
parts, too.
CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.