2004 CHEVROLET ASTRO radio

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

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

A
Accessory Power Outlets.................................3-16
Activating the Theft-Deterrent Feature................3-48
Adding Equipment to Your Air Bag-Equipped
Vehicle.......................................................1-70
Adding Washer Fluid.......................................5-38
Additional Program Information........................... 7-8
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment............................5-95
Add-On Equipment..........................................4-35
Adjusting the Speakers (Balance/Fade)......3-40, 3-43
Air Bag
Readiness Light..........................................3-26
Air Bag System..............................................1-63
Adding Equipment to Your Air
Bag-Equipped Vehicle...............................1-70
How Does an Air Bag Restrain?....................1-67
Servicing Your Air Bag-Equipped Vehicle.........1-69
What Makes an Air Bag In¯ate?....................1-67
What Will You See After an Air
Bag In¯ates?...........................................1-68
When Should an Air Bag In¯ate?...................1-67
Where Are the Air Bags?..............................1-65
Air Cleaner/Filter, Engine.................................5-21
Airbag Sensing and Diagnostic Module (SDM)...... 7-9
All-Wheel Drive...............................................5-47All-Wheel Drive (AWD) System.........................2-24
All-Wheel-Drive Service Light............................3-35
AM ...............................................................3-50
AM-FM Radio.................................................3-39
Antenna, Fixed Mast.......................................3-50
Anti-lock Brake System..................................... 4-7
Anti-Lock Brake, System Warning Light..............3-29
Appearance Care............................................5-86
Care of Safety Belts....................................5-89
Chemical Paint Spotting...............................5-93
Cleaning the Inside of Your Vehicle................5-87
Cleaning the Outside of Your Vehicle..............5-90
Finish Damage............................................5-93
Sheet Metal Damage...................................5-92
Underbody Maintenance...............................5-93
Vehicle Care/Appearance Materials................5-94
Weatherstrips..............................................5-89
Ashtrays........................................................3-17
Audio System(s).............................................3-38
AM-FM Radio.............................................3-39
Care of Your CD Player...............................3-50
Care of Your CDs........................................3-50
Fixed Mast Antenna.....................................3-50
Radio with CD............................................3-41
Rear Seat Audio (RSA)................................3-46
1

Audio System(s) (cont.)
Setting the Time for Radios with HR and
MN Buttons.............................................3-38
Setting the Time for Radios with the
Set Button..............................................3-38
Theft-Deterrent Feature................................3-47
Understanding Radio Reception.....................3-50
Automatic Headlamp System............................3-13
Automatic Transmission
Fluid..........................................................5-22
Operation...................................................2-21
Automatic Transmission Check..........................6-25
Automatic Transmission Shift Lock Control
System Check.............................................6-26
B
Backing Up....................................................4-42
Battery..........................................................5-42
Battery Replacement......................................... 2-5
Battery Run-Down Protection............................3-16
Before Leaving on a Long Trip.........................4-21
Bench Seat............................................1-11, 1-58
Body Lubrication Service..................................6-25
Brake
Parking......................................................2-24Brake (cont.)
System Inspection.......................................6-29
System Warning Light..................................3-28
Brake Adjustment............................................5-41
Brake Fluid....................................................5-39
Brake Pedal Travel.........................................5-41
Brake Wear...................................................5-41
Brakes..........................................................5-39
Braking........................................................... 4-6
Braking in Emergencies..................................... 4-9
Break-In, New Vehicle.....................................2-17
Bucket Seats, Rear.........................................1-12
Bulb Replacement...........................................5-49
Front Turn Signal Lamps..............................5-53
Halogen Bulbs............................................5-49
Headlamps.................................................5-50
Replacement Bulbs......................................5-55
Taillamps....................................................5-54
Buying New Tires...........................................5-70
C
California Fuel.................................................. 5-5
Canada ± Customer Assistance.......................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-7
2

Part C - Periodic Maintenance Inspections..........6-28
Part D - Recommended Fluids and Lubricants....6-30
Part E - Maintenance Record...........................6-32
Passenger Van Models....................................1-51
Passing.................................................4-12, 4-42
Passlock
ž......................................................2-16
Payload.........................................................4-35
Plan Ahead When Possible................................ 7-7
Playing a CD.................................................3-43
Playing the Radio...................................3-39, 3-41
Power
Accessory Outlets........................................3-16
Door Locks.................................................. 2-7
Electrical System.........................................5-96
Seat............................................................ 1-3
Steering Fluid.............................................5-37
Windows....................................................2-15
Power Steering................................................ 4-9
Programmable Automatic Door Locks.................. 2-7
Programming the HomeLink
žTransmitter...........2-31
Q
Questions and Answers About Safety Belts.........1-17
R
Radiator Pressure Cap....................................5-27
Radios..........................................................3-38AM-FM Radio.............................................3-39
Care of Your CD Player...............................3-50
Care of Your CDs........................................3-50
Radio with CD............................................3-41
Rear Seat Audio..........................................3-46
Setting the Time for Radios with HR and
MN Buttons.............................................3-38
Setting the Time for Radios with the
Set Button..............................................3-38
Theft-Deterrent............................................3-47
Understanding Reception..............................3-50
Reading Lamps..............................................2-36
Rear Air Conditioning System...........................3-21
Rear Axle......................................................5-48
Locking........................................................ 4-9
Rear Doors....................................................2-11
Rear Heating System......................................3-21
Rear Safety Belt Comfort Guides......................1-32
Rear Seat Audio (RSA)....................................3-46
Rear Seat Operation......................................... 1-7
Rear Seat Outside Passenger Positions.............1-29
Rear Seat Passengers, Safety Belts..................1-29
Rear Window Defogger....................................3-19
Rearview Mirrors.............................................2-30
Reclining Seatbacks.......................................... 1-4
Recreational Vehicle Towing.............................4-29
Reinstalling the Engine Cover...........................5-21
Remote Keyless Entry System, Operation............ 2-4
Removing the Engine Cover.............................5-17
11