Page 261 of 443

4-50 Dinghy Towing
When towing your vehicle, turn the ignition off.
To prevent your battery from draining while towing,
remove the IGN 0 fuse from the instrument panel
fuse block. Be sure to reinstall the fuse when you reach
your destination. See ªFuses and Circuit Breakersº in
the Index.
Tw o
-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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4-71
The seven-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
Red: Battery Feed
Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)
If you need to tow a light
-duty trailer with a standard
four
-way round pin connector, an adapter connector is
included with your vehicle.Instrument Panel Jumper Wiring Harness
This harness is included with the heavy-duty trailer
wiring package. The harness is for an electric trailer
brake controller and includes a trailer battery feed fuse.
This harness and fuse should be installed by your dealer
or a qualified service center.
Page 324 of 443

6-3
CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts and
other fasteners. ªEnglishº and ªmetricº
fasteners can be easily confused. If you use
the wrong fasteners, parts can later break
or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind noise
and affect windshield washer performance. Check with
your dealer before adding equipment to the outside of
your vehicle.
Fuel (Gasoline)
The 8th digit of your vehicle identification number
(VIN) shows the code letter or number that identifies
your engine. You will find the VIN at the top left of the
instrument panel. See ªVehicle Identification Numberº
in the Index.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E
-85); also
see ªFuel E
-85 (85% Ethanol)º following. In all other
engines, including the 5.3L V8 (VIN Code T), use only
regular unleaded gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane of
87 or higher. If the octane is less than 87, you may get a
heavy knocking noise when you drive. If it is bad
enough, it can damage your engine. A little pinging
noise when you accelerate or drive uphill is considered
normal. This does not indicate a problem exists or that a
higher
-octane fuel is necessary.
Page 334 of 443
6-13
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Automatic Transmission Dipstick (If Equipped)
F. Engine Oil Fill
G. FanH. Remote Negative (-) Terminal (GND)
I. Power Steering Fluid Reservoir
J. Remote Positive (+) Terminal
K. Brake Master Cylinder Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer Fluid Reservoir
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6-14
When you open the hood on the VORTEC 8100 V8 engine you'll see the following:
A. Engine Air Cleaner/Filter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Oil Dipstick
E. Automatic Transmission Dipstick
F. Engine Oil FillG. Fan
H. Remote Negative (
-)
Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid ReservoirK. Brake Master Fluid Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer
Fluid Reservoir
Page 390 of 443

6-69
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.
Windshield Wipers
The windshield wiper motor is protected by an internal
circuit breaker and a fuse. If the motor overheats due to
heavy snow, etc., the wiper will stop until the motor
cools. If the overload is caused by some electrical
problem and not snow, etc., 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, circuit breakers
and fusible thermal links. 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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6-70
Instrument Panel Fuse Block
The fuse block access door
is on the driver's side edge
of the instrument panel. Pull
off the cover to access the
fuse block.
You can remove fuses with a fuse extractor which is
mounted to the fuse block access door. To remove fuses
if you don't have a fuse extractor, hold the end of the
fuse between your thumb and index finger and pull
straight out.
You may have spare fuses located behind the fuse block
access door. These can be used to replace a bad fuse.
However, make sure it is of the correct amperage.
Fuse Usage
HVAC 1 Climate Control System
IGN 3 Ignition, Power Seats
BRAKE Anti
-Lock Brake System
Page 392 of 443
6-71
Fuse Usage
HTR A/C Climate Control System
IGN 0 PRND321 Display,
Odometer, PCM
CRUISE Cruise Control, Instrument Cluster
4WD Four
-Wheel Drive System,
Auxiliary Battery
TURN Exterior Lamps, Turn Signals,
Hazard Lamps
RR WIPER Rear Window Wiper
WS WPR Windshield Wipers
SEO IGN Special Equipment Option,
Ignition, OnStar
ILLUM Interior Lamps
IGN 1 Ignition, Instrument Panel
SEO ACCY Special Equipment Option
Accessory, Cellular Telephone
L BODY Retained Accessory Power Relay
CRANK Starting SystemFuse Usage
AIR BAG Air Bag
MIR/LOCK Power Mirrors, Power Door Locks
SEAT Power Seat Circuit Breaker
DR LOCK Power Door Locks
RAP #1 Retained Accessory Power Relay
LOCK Power Door Locks
INT PRK Interior Lamps
UNLOCK Power Door Locks
DRV UNLOCK Power Door Lock Relay
L DOOR Power Door Lock Relay
PWR WDO Power Window Circuit Breaker
RDO I Audio System, OnStar
RAP #2 Rear Power Windows, Sunroof,
Radio, OnStar
LOCK Power Door Lock Relay
UNLOCK Power Door Lock Relay