
Headlamp Wiring
The headlamp wiring is protected by a circuit breaker in
the lamp switch. An electrical overload will cause the
lamps to ¯icker on and off, or in some cases to remain
off. If this happens, have your headlamp wiring
checked right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by a circuit
breaker and a fuse. If the motor overheats due to heavy
snow, etc., the wiper will stop until the motor cools.
Although the circuit is protected from electrical overload,
overload due to heavy snow, etc., may cause wiper
linkage damage. Always clear ice and heavy snow from
the windshield before using the windshield wipers. If
the overload is caused by some electrical problem and
not snow, etc., be sure to get it ®xed.
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 and
closes, protecting the circuit until the problem is ®xed 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 ®res 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.
Spare fuses and a fuse puller are located in the
underhood fuse block. You can remove fuses with the
fuse puller. Remember to replace any of the spare fuses
you use, so you will have some if you ever need them
again.
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.
There are two fuse blocks in your vehicle: one is inside
the vehicle and one is in the engine compartment.
5-96

Instrument Panel Fuse Block
The fuse block is located on the lower portion of the
instrument panel on the driver's side.
Fuse/Circuit
Breaker Usage
1 Stop/Turn/Hazard Lamps, Center
High Mounted Stop Lamp, Anti-Lock
Brakes
2 Radio Accessory, Rear Seat Audio
Controls
5-97

Fuse/Circuit
Breaker Usage
3 Courtesy Lamps, Glove Box Lamp,
Dome Reading Lamps, Vanity Mirror
Lamps, Courtesy Lamps
4 Daytime Running Lamps Relay,
Instrument Panel Cluster
5 Rear Defogger
6 Cruise Module, Truck Body Control
Module, Instrument Panel Cluster,
Cruise Control Switch,
Electrochromic Mirror
7 Power Outlets, Subwoofer Ampli®er
8 Crank Circuit Fuse, Park/Neutral
Switch, Starter Enabler Relay
9 License Plate Lamp, Tailamps,
Parking Lamps, Ashtray Lamp,
Panel Lights, Trailer Taillamps, Front
and Rear Sidemarker Lamps, Door
Switch Illumination, Headlamp
Switch Illumination, Rear Seat Audio
Illumination, Truck Body Control
Module
10 Air Bag System
11 Not UsedFuse/Circuit
Breaker Usage
12 Blower Motor, Rear Air Conditioning
Relay Coil, Front Cont. Temp. Door
Motor, HI Blower Relay, Defogger
Timer Coil
13 Cigarette Lighter, Door Lock
Switches, Dutch Door Release
Module
14 Cluster Illumination, Climate
Controls, Chime Module, Radio
Illumination, Rear Heat Switch
Illumination, Rear Wiper/Washer
Switch Illumination, Rear Liftgate
Switch Illumination, Remote
Cassette Illumination, Overhead
Console, Truck Body Control
Illumination
15 Truck Body Module, Headlamp
Relay
16 Front Turn Signals, Rear Turn
Signals, Trailer Turn Signals,
Back-Up Lamps, Brake
Transmission Shift Interlock Solenoid
17 Front Wipers, Front Washer Pump
5-98

Fuse/Circuit
Breaker Usage
18 VCM-Ign 3, VCM-Brake, Cruise
Stepper Motor Signal, ATC Module
19 Instrument Panel Radio: ATC (Main
Feed), 2000 Series (Standby)
20 PRNDL/Odometer, Shift A and Shift
B Solenoids, 3±2 Downshift
Solenoid, Instrument Panel Cluster,
VCM Module
21 Powr Adjust Mirrors
22 Not Used
23 Rear Wiper, Rear Washer Pump
24 Not Used
A (Circuit Breaker) Power Door Lock
Relay, 6±Way Power Seats
B (Circuit Breaker) Power WindowsUnderhood Fuse Block
The underhood fuse block is located toward the rear of
the engine compartment on the driver's side of the
vehicle.
Lift the hood and open the cover to gain access to this
fuse block.
A fuse puller is included in the underhood fuse block.
You will also ®nd spare fuses.
5-99

Feed Usage
AUX B Up®tter Battery Feed
AUX A Up®tter Accessory Feed
Relays Usage
A/C Relay
(Rear Heat
and A/C)Rear/Heat and Air ConditioningRelays Usage
Up®tter-ACCY
RelayUp®tter Accessory
Starter Enable
RelayStarter
A/C Enable
RelayAir Conditioning
Headlamps
RelayHeadlamps
Fuel Pump
RelayFuel Pump
Fuse/Circuit
BreakerUsage
UPFITTER-
BATTUp®tter Battery Power Stud, Trailer
Wiring Harness
UPFITTER-
ACCYUp®tter Accessory Relay
Spare Not used
Spare Not used
Spare Not used
ECM-1BFuel Pump Relay and Motor, VCM,
Oil Pressure Switch/Sender
HORN Horn Relay and Horn
5-100

Fuse/Circuit
BreakerUsage
A/C COMPAir Conditioning Enable Relay and
Compressor
RR HTR/AC Rear Heater and Air Conditioning
ATC Active Transfer Case-L Van
FRT HVAC Front Heater and Air Conditioning
ENG-IOxygen Sensors, Camshaft Position
Sensor, Mass Air Flow Sensor,
Evaporative Emission Canister Vent
Solenoid
IGN-E Air Conditioning Enable Relay Coil
ECM-IFuel Injectors 1±6, Crankshaft
Position Sensot, VCM, Coil Driver
Module (EST), Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
Blank Not Used
Blank Not UsedFuse/Circuit
BreakerUsage
DIODE-1 Air Conditioning
Blank Not Used
Blank Not Used
Blank Not Used
LIGHTINGCourtesy Fuse, Power Adjust
Mirrors Fuse, Truck Body Control
Battery Fuse
BATTPower Accessory Circuit Breaker,
Stop/Hazard Fuse, Auxiliary Power
Fuse, Cigarette Lighter Fuse, Radio
Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABSElectronic Brake
Control Module
Blank Not Used
RAP Radio Accessory, Power Windows
HTD MIR/RR
DEFOGRear Window Defogger,Climate
Control Head
5-101

Driver
Position, Safety Belt.....................................1-18
Driver Information System................................2-38
Driving
At Night.....................................................4-14
City...........................................................4-19
Defensive..................................................... 4-2
Drunken....................................................... 4-3
Freeway.....................................................4-20
Hill and Mountain Roads..............................4-22
In Rain and on Wet Roads...........................4-16
Winter........................................................4-24
Driving On Grades..........................................4-42
Driving on Snow or Ice....................................4-25
Driving Through Deep Standing Water...............4-18
Driving Through Flowing Water.........................4-18
Driving with a Trailer.......................................4-41
E
Electrical System
Add-On Equipment......................................5-95
Fuses and Circuit Breakers...........................5-96
Headlamp Wiring.........................................5-96
Power Windows and Other Power Options......5-96
Windshield Wiper Fuses...............................5-96
Emissions Inspection and Maintenance
Programs...................................................3-33Engine
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-42
Check and Service Engine Soon Light............3-30
Coolant......................................................5-25
Coolant Heater............................................2-20
Coolant Temperature Gage...........................3-30
Cooling System Inspection............................6-28
Cover........................................................5-17
Drive Belt Routing......................................5-105
Engine Compartment Overview......................5-12
Exhaust.....................................................2-28
Fan Noise..................................................5-36
Oil .............................................................5-13
Overheating................................................5-28
Starting......................................................2-19
Engine Coolant Level Check.............................6-24
Engine Oil Additives........................................5-16
Engine Oil Level Check...................................6-24
Entry Lighting.................................................3-15
Erasing HomeLinkžButtons..............................2-33
Event Data Records (EDR)................................ 7-9
Except Cargo Vans.................................1-38, 1-47
Exit Lighting...................................................3-15
Express-Down Window....................................2-15
Extender, Safety Belt.......................................1-34
Exterior Lamps...............................................3-12
5

F
Filter
Engine Air Cleaner......................................5-21
Finding a Station....................................3-39, 3-41
Finish Care....................................................5-90
Finish Damage...............................................5-93
Fixed Mast Antenna........................................3-50
Flash-to-Pass................................................... 3-7
Flat Tire........................................................5-74
Flat Tire, Changing.........................................5-75
Fluid
Automatic Transmission................................5-22
Power Steering...........................................5-37
Windshield Washer......................................5-38
FM ...............................................................3-50
Following Distance..........................................4-41
Footnotes................................................6-7, 6-16
Front Axle......................................................5-48
Fuel............................................................... 5-4
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-9
Filling Your Tank........................................... 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-36Fuel (cont.)
Gasoline Octane........................................... 5-4
Gasoline Speci®cations.................................. 5-5
Low Warning Light.......................................3-37
System Inspection.......................................6-28
Fuel Regulator................................................2-19
Fuses
Fuses and Circuit Breakers...........................5-96
Windshield Wiper.........................................5-96
G
Gage
Check Gages Warning Light..........................3-36
Engine Coolant Temperature.........................3-30
Fuel..........................................................3-36
Oil Pressure...............................................3-34
Speedometer..............................................3-25
Voltmeter Gage...........................................3-28
Gasoline
Octane........................................................ 5-4
Speci®cations............................................... 5-5
Gate Operator and Canadian Programming........2-33
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
6