2004 CHEVROLET ASTRO brake light

Driving too fast through large water puddles or even
going through some car washes can cause problems,
too. The water may affect your brakes. Try to avoid
puddles. But if you can not, try to slow down before you
hit them.
{CAUTION:
Wet brakes can cause accidents. They will not
work as well in a quick stop and may cause
pulling to one side. You could lose control of
the vehicle.
After driving through a large puddle of water
or a car wash, apply your brake pedal lightly
until your brakes work normally.
4-17

Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission ¯uid (don't over®ll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you ®nd them quickly. If
you're trailering, it's a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
If you have the optional trailering package, your vehicle
will have an eight-wire harness, including the center
high-mounted stoplamp battery feed wire. The harness
is stored on the passenger's side of the vehicle near
the rear wheel well. This harness has a 30 amp battery
feed wire and no connector, and should be wired by
a quali®ed electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight-wire trailer
harness and the other connector to the wiring harness
on the trailer. Be sure the wiring harness on the trailer is
taped or strapped to the trailer's frame rail and leave
it loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. The eight-wireharness must be routed out of your vehicle between the
rear door and the ¯oor, with enough of the harness
left on both sides so that the trailer or the body won't pull
it. If you do not have the optional trailering package,
your vehicle will still have a trailering harness. The
harness is located near the passenger's side rear wheel
well. It consists of six wires that may be used by
after-market trailer hitch installers.
The technician can use the following color code chart
when connecting the wiring harness to your trailer.
·Brown: Rear lamps.
·Yellow: Left stoplamp and turn signal.
·Dark Green: Right stoplamp and turn signal.
·White (Heavy Gage): Ground.
·Light Green: Back-up lamps.
·White (Light Gage): Center High-Mounted Stoplamp.
·Blue: Auxiliary circuit (eight-wire harness only).
·Orange: Fused auxiliary (eight-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly so it won't
be damaged.
4-44

·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
Appearance
Care on page 5-86.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal ®rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes will not work well. That
could lead to an accident. When you hear the
brake wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are ®rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque speci®cations.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-29.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
5-41

Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. But please follow the numbered steps to
do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
·They contain acid that can burn you.
·They contain gas that can explode or
ignite.
·They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that would not be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a
12±-volt battery with a negative ground system.
Notice:If the other vehicle's system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake ®rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) and a manual
transmission in NEUTRAL.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off all
lamps that aren't needed as well as radios. This will
avoid sparks and help save both batteries. In
addition, it could save your radio!
5-43

(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªLTº as
the ®rst two characters in the tire size means a light
truck tire engineered to standards set by the U. S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
ªRº means radial ply construction; the letter ªDº means
diagonal or bias ply construction; and the letter ªBº
means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations.Tire Terminology and De®nitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire's height to its
width. Light Truck (LT-Metric) Tire
5-63

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
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