wiring GMC ENVOY 2001 Owners Manual

2-14
Endgate/Liftgate
CAUTION:
It can be dangerous to drive with the rear
window, endgate or liftgate open because carbon
monoxide (CO) gas can come into your vehicle.
You can't see or smell CO. It can cause
unconsciousness and even death.
If you must drive with the rear window, endgate
or liftgate open or if electrical wiring or other
cable connections must pass through the seal
between the body and the rear window, endgate
or liftgate:

Make sure all other windows are shut.

Turn the fan on your heating or cooling
system to its highest speed with the setting
on VENT or OUTSIDE AIR. That will force
outside air into your vehicle. See ªComfort
Controlsº in the Index.

If you have air outlets on or under the
instrument panel, open them all the way.
See ªEngine Exhaustº in the Index.
Endgate Release
To open a manual lock system from the outside,
insert the key into the lock and turn it counterclockwise
to unlock the glass.
To open a power lock system from the outside, insert the
key into the lock button and turn it counterclockwise.
All the doors will then unlock.
If your vehicle is equipped with the keyless entry system,
your vehicle does not have a lock on the endgate. It is
equipped with a pushbutton to release the glass.
You may also use the keyless entry system, or the
power door locks (if equipped).
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2-48
As you signal a turn or a lane change, if the arrows flash
more quickly than normal, a signal bulb may be burned
out and other drivers won't see your turn signal.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows don't go on at all when you
signal a turn, check the fuse (see ªFuses and Circuit
Breakersº in the Index) and for burned
-out bulbs.
If you have a trailer towing option with added wiring for
the trailer lamps, a different turn signal flasher is used.
With this flasher installed, the signal indicator will flash
even if a turn signal bulb is burned out. Check the front
and rear turn signal lamps regularly to make sure they
are working.
Turn Signal On Chime
If your turn signal is left on for more than 3/4 of a mile
(1.2 km), a chime will sound at each flash of the turn
signal. To turn off the chime, move the turn signal lever
to the off position.
Headlamp High/Low-Beam Changer
To change the headlamps from low beam to high or
high to low, pull the multifunction lever all the way
toward you. Then release it.
When the high beams
are on, this indicator light
on the instrument panel
cluster will also be on.
Flash-to-Pass
This feature lets you use your high-beam headlamps to
signal a driver in front of you that you want to pass. It works
even if your headlamps are in the automatic position.
To use it, pull the turn signal lever toward you, but not
so far that you hear a click.
If your headlamps are in the automatic position or on
low beam, your high
-beam headlamps will turn on.
They'll stay on as long as you hold the lever toward you
and the high
-beam indicator on the instrument panel
cluster will come on. Release the lever to return to
normal operation.
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2-90
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag 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 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.
If the light doesn't come on then, have it fixed so
it will be ready to warn you if there is a problem.
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4-55 Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have
extra wiring and a heavy
-duty turn signal flasher
(included in the optional trailering package).
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when they are not. It's important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much
that they would get hot and no longer work well.On a long uphill grade, shift down and reduce your
speed to around 45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating.
If you have an automatic transmission, you should
use THIRD (3) when towing a trailer. Operating your
vehicle in THIRD (3) when towing a trailer will
minimize heat buildup and extend the life of your
transmission. Or, if you have a manual transmission,
it's better not to use FIFTH (5) gear, just drive in
FOURTH (4) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine off.
If you do get the overheat warning, see ªEngine
Overheatingº in the Index.
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4-58 Trailer Wiring Harness
The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy
-duty trailer wiring is an
eight
-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger
-side frame
crossmember on two
-door vehicles or on the driver's
side corner frame rear crossmember on four
-door
vehicles. The heavy
-duty trailer wiring is fused in the
engine compartment fuse block. See ªFuses and Circuit
Breakersº in the Index. Both harnesses have no
connector and should be wired by a qualified
electrical technician. The technician can use the
following color code chart when connecting the
wiring harness to your trailer.
Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight
-wire harness only).

Red: Use for battery charging; it connects to the
starter solenoid (eight
-wire harness only).

Light Green: Back
-up lamps.

Brown: Taillamps and parking lamps.

Yellow: Left stoplamp and turn signal.

Dark Green: Right stoplamp and turn signal.

White: Ground wire.

Light Blue: Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break,
but not so loose that it drags on the ground. 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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6-63
Electrical System
Add-On Electrical Equipment
NOTICE:
Don't add anything electrical to your vehicle unless
you check with your dealer first. Some electrical
equipment can damage your vehicle and the
damage wouldn't be covered by your warranty.
Some add
-on electrical equipment can keep other
components from working as they should.
Your vehicle has an air bag system. Before attempting to
add anything electrical to your vehicle, see ªServicing
Your Air Bag
-Equipped Vehicleº in the Index.
Headlamps
The headlamp wiring is protected by an internal circuit
breaker. An electrical overload will cause the lamps to go
on and off, or in some cases to remain off. If this happens,
have your headlamp wiring checked right away.
Windshield Wipers
The windshield wiper motor is protected by a circuit breaker
and a fuse. If the motor overheats due to heavy snow or ice,
the wiper will stop until the motor cools. If the overload is
caused by some electrical problem, be sure to get it fixed.
Power Windows and Other Power Options
Circuit breakers protect the power windows and other
power accessories. When the current load is too heavy,
the circuit breaker opens and closes, protecting the
circuit until the problem is fixed or goes away.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses and circuit
breakers. This greatly reduces the chance of fires caused
by electrical problems.
Look at the silver
-colored band inside the fuse. If the band
is broken or melted, replace the fuse. Be sure you replace
a bad fuse with a new one of the identical size and rating.
If you ever have a problem on the road and don't have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle that
you can get along without
-- like the radio or cigarette
lighter
-- and use its fuse, if it is the correct amperage.
Replace it as soon as you can.
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