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Proper front wheel alignment must be maintained in
order to ensure efficient steering, good directional
stability, and prevent abnormal tire wear. If you notice
unusual tire wear or your vehicle is pulling one way
or the other, the alignment may need to be reset. If you
notice your vehicle vibrating when driving on a smooth
road, your wheels may need to be balanced.
Tightening the Wheel Nuts
{CAUTION:
Wheel nuts that are not tight can work loose. If
all the nuts on a wheel come off, the wheel can
come off the vehicle, causing a crash. All
wheel nuts must be properly tightened. Follow
the rules in this section to be sure they are.
This section lets you know how often to check the
tightness of the wheel nuts on your vehicle and how tight
they must be.First, use these pictures to decide what kind of wheels
you have.
Then, follow the steps below for the wheels you have.
Hub-Piloted Wheels, 8-Hole or 10-Hole
The studs and nuts used with these wheels have
right-hand threads.
1. With intermittent pilot pads, position a pad at
12 o’clock to center the wheel and reduce run-out.
2. Put the tire and rim assembly on the axle hub.
Install the outer rear tire and rim assembly so
that its valve stem is exactly opposite the valve stem
on the inner tire and rim assembly. Hub-Piloted Type,
8-Hole
Hub-Piloted Type,
10-Hole
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Windshield Wiper Fuses
The windshield wiper motor is protected by a circuit
breaker inside the motor and a circuit breaker or fuse in
the fuse block. If the motor overheats, the wipers will
stop until the motor cools. If the overload is caused by
an electrical problem, be sure to get it fixed.
Fusible Links
A fusible link is a short piece of wire several gauge
sizes smaller than the circuit it protects. It will melt in an
overload situation, opening the circuit.
Your starter and other circuits have these fusible links.
The size is printed on the insulation. If the insulation
is burned beyond recognition, consult your GM dealer
for the proper size. Replace a fusible link with one of the
same size and insulation type. Fusible link insulation
is a special purpose high-temperature material.
The hydraulic brake booster motor feed circuit and
starter circuit are protected by a fusible link. Vehicles
with a diesel engine have a fusible link for the intake
heater feed circuit.
Power Windows and Other Power
Options
Circuit breakers in the fuse panel protect the power
windows and other power accessories. When the current
load is too heavy, the circuit breaker opens. This
protects the circuit until the current load returns to
normal or the problem is fixed.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers,
maxi-fuses and fusible links. This greatly reduces the
chance of a fire caused by an electrical problem. There
may be a fuse taped to the wiring harness near the
hydraulic brake booster.
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Instrument Panel Fuse Block
There are two instrument panel fuse blocks located behind the instrument panel on the passenger’s side of
the vehicle.
Be sure to replace fuses with fuses of the same rating. Do not use fuses of higher amperage than those indicated on
the fuse block.
Fuse Block 1
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Circuit Breaker Usage
1 Stoplamps
2 Center High Mounted Stop Lamps
3 Parking Lamps
4 Powertrain Control Module
5 Auxiliary Wiring
6 Heater/Air Conditioning
7 Hazard Warning FlashersCircuit Breaker Usage
8 Power Post
9 Courtesy Lamps
10Warning Lights, Gages and
Indicators
11 Crank
12 Rear Axle
13Trailer Turn Signals/Hazard Warning
Flashers
14 Radio/Chime
15 Daytime Running Lamps
16 Air Bag System
17 Exterior/Interior Lamps
18 Parking Brake
19 Accessory Power
20 Ignition
21 Sidemarker Lamps
22 Turn Signal/Backup Lamps
23 Transmission
24 Chassis
A Spare
B Spare Fuse Block 2
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Underhood Fuse Block
When a circuit goes out, the problem could be in either
the primary or secondary underhood fuse blocks.
These blocks uses blade-type fuses.
Both underhood fuse
blocks are located in the
engine compartment,
on the passenger’s side of
the vehicle.
To access the fuse blocks, gently squeeze both sides of
the cover to unlatch the tabs at the top. Then, unsnap
both attachments at the bottom and remove the cover.
Be sure to replace fuses with fuses of the same
rating. Do not use fuses of higher amperage than those
indicated on the fuse block.Relay Usage
NOTE 1 LG4 Powertrain Control Valve,
L18/LB7 Fuel Pump, LG5 Heated
Fuel
IGN B Ignition
STARTER Starter
HORN Horn
IGN A Ignition Primary Underhood
Fuse Block
Primary Underhood Fuse Block
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Relay Usage
PTO Power Take-Off
REVERSE Reverse
NEUTRAL
STARTNeutral Start
Fuse Usage
RR DEFOG Rear Defog
ENG 1 Engine 1
ENG 3 Engine 3
PCM-B Powertrain Control Module
BLANK Empty
ENG 4 Engine 4
ENG 2 Engine 2
HTD FUEL Heated Fuel
BLANK EmptyFuse Usage
BLANK Empty
BLANK Empty
A/C COMP Air Conditioning Compressor
ABS 1 Anti-Lock Brake System 1
ABS 2 Anti-Lock Brake System 2
ABS 3 Anti-Lock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN Horn
NOTE 2L18/LB7 Fuel, LG4 Powertrain
Control Valve, LG5 Electronic
Control Module
BLANK Empty
STUD A Spare
STUD B Spare
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Fuse Usage
IGN 1 Ignition 1
IGN 4 Ignition 4
IGN 3 Ignition 3
BATT/HAZ Battery/Hazard Warning Flashers
HEADLAMP Headlamps
LIGHTING Interior/Exterior Lamps
HVAC Comfort Control System
NOTE C4/C5 Electric Brake,
C6/C7/C8 Brake Lamps
Capacities and Speci cations
Capacities and Speci cations
Engine RPO
7.2L L6 HEUI Fuel System LG5
8.1L V8 SPFI Fuel System L18
7.8L L6 Common Rail Fuel System LG4
6.6L V8 Common Rail Fuel System LB7/LLY Secondary Underhood
Fuse Block
5-93
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At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light (if equipped)
and all your belts, buckles, latch plates, retractors
and anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from doing
its job, have it repaired. Have any torn or frayed
safety belts replaced.
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-80.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. Part C tells you what to use.
Body Lubrication Service
Lubricate all exposed surfaces such as door checks,
door lock bolts, lock strike plates, door hinge bushings,
latches and dovetail bumper wedges. Where oil
holes are provided a dripless oil can be used. The seat
adjusters, seat track, door weatherstrips and rubber
cap bumpers should also be lubricated. Part C tells you
what to use. More frequent lubrication may be required
when exposed to a corrosive environment.
Parking Brake Check
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability.
6-25