2003 CHEVROLET SILVERADO wiring

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.
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.
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.
To remove fuses, hold the end of the fuse between your
thumb and index ®nger 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.
5-110

Fuses Usage
RT TRNRight Turn Signals and
Sidemarkers
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2 Not Used
LOCKS Power Door Lock System
ECC Not Used
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Power Windows Circuit
Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body ControllerCenter Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
Device Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPFIT Up®tter (Not Used)
SL RIDERide Control Harness
Connection
HDLR 2 Headliner Wiring Connector
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
5-112

*1Ð Gasoline Engine and Diesel Engine.
*2Ð Gasoline Engine; ECMRPV Ð Diesel Engine.
*3Ð Gasoline Engine; FUEL HT Ð Diesel Engine.
*4Ð Gasoline Engine; ECM I Ð Diesel Engine.
*5Ð IGN/EDU
Fuses Usage
GLOW PLUGDiesel Glow Plugs and Intake
Air Heater
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power OutletÐRear
Cargo Area and Instrument
Panel
Fuses Usage
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
5-115

Fuses Usage
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Not Used
AUX PWRAuxiliary Power Outlet Ð
Console
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control SystemFuses Usage
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
02B Oxygen Sensors
SIRSupplemental In¯atable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
5-116

H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamp High/Low Beam Changer.................... 3-9
Headlamps....................................................5-59
Bulb Replacement.......................................5-59
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-61
Halogen Bulbs............................................5-59
Pickup Box Identi®cation and Fender Marker
Lamps....................................................5-65
Roof Marker Lamps.....................................5-62
Headphones.................................................3-116
Heated Seats................................................... 1-5
Heating.........................................................3-30
Heavy-DutyTrailer Wiring Harness Package........4-90
Highway Hypnosis...........................................4-45
Hill and Mountain Roads..................................4-46
Hitches..........................................................4-85
Hood.............................................................. 5-8
Checking Things Under.................................. 5-8
Release....................................................... 5-9
Horn............................................................... 3-7
How to Add Coolant to the Coolant Surge Tank
Gasoline Engines........................................5-38
How to Add Fluid............................5-25, 5-28, 5-29
How to Check and Add Fluid............................5-30
How to Check Lubricant...................................5-55How to Check Power Steering Fluid..................5-43
How to Check........................5-23, 5-26, 5-28, 5-70
How to Inspect...............................................5-21
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-15
Hydraulic Clutch System Check........................6-14
Hydraulic Clutch.............................................5-29
Hydroplaning..................................................4-41
I
If No Steam Is Coming From Your Engine..........5-35
If Steam Is Coming From Your Engine...............5-34
If the Light is Flashing.....................................3-50
If the Light Is On Steady.................................3-50
If You Are Stuck in Sand, Mud, Ice or Snow.......4-52
If You Do Decide To Pull A Trailer.....................4-68
If You're Caught in a Blizzard...........................4-50
Ignition Positions.............................................2-20
Ignition Transmission Lock Check......................6-15
Infants and Young Children, Restraints...............1-34
In¯ation -- Tire Pressure..................................5-69
Inspection......................................................6-18
Brake System.............................................6-18
Engine Cooling System................................6-17
Exhaust System..........................................6-17
Fuel System...............................................6-17
Part C - Periodic Maintenance.......................6-17
8

Tires (cont.)
Changing a Flat Tire....................................5-80
Dual Tire Operation.....................................5-70
If a Tire Goes Flat.......................................5-79
In¯ation -- Tire Pressure...............................5-69
Inspection and Rotation................................5-71
Uniform Tire Quality Grading.........................5-75
Wheel Alignment and Tire Balance.................5-76
Wheel Replacement.....................................5-76
When It Is Time for New Tires......................5-73
To Use the Engine Coolant Heater....................2-24
Top Strap Anchor Location...............................1-44
Top Strap......................................................1-42
Torque Lock (Automatic Transmission)...............2-48
Total Weight on Your Vehicle's Tires..................4-84
Tow/Haul Mode Light.......................................3-53
Tow/Haul Mode, Overdrive Disable....................3-53
Tow/Haul Mode
(Automatic Transmission)..............................2-28
Towing..........................................................4-95
Power Take-Off (PTO)..................................4-95
Recreational Vehicle.....................................4-55
Towing a Trailer..........................................4-68
Your Vehicle...............................................4-55
TRACTION ACTIVE........................................3-70
Traction.........................................................4-10
Assist System (TAS)....................................4-10
Manual Selectable Ride................................4-12
Off Light.....................................................3-46Traction (cont.)
Trailer Brakes.................................................4-85
Trailer Wiring Harness.....................................4-89
Trailer...........................................................4-67
Recommendations.......................................4-67
TRANS HOT IDLE ENGINE (Allison
Transmission
žOnly).....................................3-71
Transfer Case and Front Axle (Four-Wheel Drive)
Inspection...................................................6-18
Transfer Case........................................5-54, 5-56
TRANSMISSION HOT.....................................3-70
Transmission Operation, Automatic....................2-25
Transmission Operation, Manual........................2-29
Transmission, Transaxle, Transfer Case Unit
Repair Manual............................................7-10
Transmission..................................................5-23
Fluid, Automatic..................................5-23, 5-26
Fluid, Manual..............................................5-28
Temperature Gage.......................................3-47
Up-Shift Light..............................................3-43
Transportation Options...................................... 7-7
Traveling to Remote Areas...............................4-26
Trip Information Button....................................3-55
Trip Odometer................................................3-35
Truck-Camper Loading Information....................4-65
Turn and Lane Change Signals.......................... 3-8
TURN SIGNAL ON.........................................3-71
Turn Signal/Multifunction Lever........................... 3-7
Turn Signals When Towing a Trailer..................4-87
17