2003 CHEVROLET BLAZER brake

Trailer Wiring Harness
The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy-duty trailer wiring is an
eight-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger-side frame
crossmember on two-door vehicles or on the driver's
side corner frame rear crossmember on four-door
vehicles. The heavy-duty trailer wiring is fused in the
engine compartment fuse block. See
Fuses and Circuit
Breakers on page 5-85. Both harnesses have no
connector and should be wired by a quali®ed electrical
technician. The technician can use the following
color code chart when connecting the wiring harness to
your trailer.
·Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight-wire harness only).
·Red: Use for battery charging; it connects to the
starter solenoid (eight-wire harness only).
·Light Green: Back-up lamps.
·Brown: Taillamps and parking lamps.
·Yellow: Driver's side stoplamp and turn signal.
·Dark Green: Passenger's side stoplamp and turn
signal.
·White: Ground wire.
·Light Blue: Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you
leave it loose enough so the wiring doesn't bend or
break, but not so loose that it drags on the ground. Store
the harness in its original place. Wrap the harness
together and tie it neatly so it won't be damaged.
4-65

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-5
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-6
Filling a Portable Fuel Container.......................5-8
Checking Things Under
the Hood......................................................5-8
Hood Release................................................5-9
Engine Compartment Overview.......................5-10
Engine Oil...................................................5-11
Engine Air Cleaner/Filter................................5-15
Automatic Transmission Fluid.........................5-17
Manual Transmission Fluid.............................5-20
Hydraulic Clutch...........................................5-21
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-25
Engine Overheating.......................................5-25
Cooling System............................................5-27
Engine Fan Noise.........................................5-34Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
Rear Axle.......................................................5-45
Four-Wheel Drive............................................5-45
Front Axle......................................................5-46
Bulb Replacement..........................................5-47
Halogen Bulbs..............................................5-47
Headlamps..................................................5-48
One-Piece Front Turn Signal Lamps................5-50
Two-Piece Front Turn Signal Lamps................5-50
Taillamps.....................................................5-51
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
In¯ation -- Tire Pressure................................5-55
Tire Inspection and Rotation...........................5-56
When It Is Time for New Tires.......................5-57
Buying New Tires.........................................5-58
Uniform Tire Quality Grading..........................5-59
Wheel Alignment and Tire Balance..................5-60
Wheel Replacement......................................5-60
Tire Chains..................................................5-62
Section 5 Service and Appearance Care
5-1

Filling a Portable Fuel Container
{CAUTION:
Never ®ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
·Dispense gasoline only into approved
containers.
·Do not ®ll a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed or
on any surface other than the ground.
·Bring the ®ll nozzle in contact with the
inside of the ®ll opening before operating
the nozzle. Contact should be maintained
until the ®lling is complete.
·Don't smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start a ®re. These include liquids like fuel,
oil, coolant, brake ¯uid, windshield washer and
other ¯uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-8

A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Automatic Transmission Dipstick (If Equipped)
F. Power Steering Reservoir
G. Brake Master Cylinder Reservoir
H. Engine Air Cleaner/Filter
I. Clutch Master Cylinder Reservoir
J. Engine Compartment Fuse Block
K. Windshield Washer Fluid ReservoirEngine Oil
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The oil dipstick handle is a
yellow ring located in the
engine compartment
toward the passenger side
of the vehicle. See
Engine Compartment
Overview on page 5-10for
more information on
location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
5-11

Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50ÉF
(10ÉC). If it's colder than 50ÉF (10ÉC), drive the vehicle
in THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold ¯uid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for ®ve minutes if outside temperatures are
50ÉF (10ÉC) or more. If it's colder than 50ÉF (10ÉC), you
may have to idle the engine longer. Should the ¯uid
level be low during this cold check, you
mustcheck the
¯uid hot before adding ¯uid. Checking the ¯uid hot
will give you a more accurate reading of the ¯uid level.
Checking the Fluid Level
Prepare your vehicle as follows:
1. Park your vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in PARK (P).3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position
the shift lever in PARK (P).
4. Let the engine run at idle for three minutes or more.
Then, without shutting off the engine, follow
these steps:
The transmission dipstick
handle has this symbol
on it.
The transmission dipstick is located near the center of
the engine compartment. See
Engine Compartment
Overview on page 5-10for more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
5-18

Brakes
Brake Fluid
Your brake master cylinder reservoir is ®lled with DOT-3
brake ¯uid. SeeEngine Compartment Overview on
page 5-10for the location of the reservoir.
There are only two reasons why the brake ¯uid level in
the reservoir might go down. The ®rst is that the
brake ¯uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the ¯uid level goes back up. The other reason is
that ¯uid is leaking out of the brake system. If it is, youshould have your brake system ®xed, since a leak
means that sooner or later your brakes won't work well,
or won't work at all.
So, it isn't a good idea to ªtop offº your brake ¯uid.
Adding brake ¯uid won't correct a leak. If you add ¯uid
when your linings are worn, then you'll have too
much ¯uid when you get new brake linings. You should
add (or remove) brake ¯uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake ¯uid, it can spill on
the engine. The ¯uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
¯uid only when work is done on the brake
hydraulic system. See ªChecking Brake Fluidº
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake ¯uid. See
Part C: Periodic
MaintenanceInspections on page 6-31.
5-37

Checking Brake Fluid
You can check the brake ¯uid without taking off the cap.
Just look at the brake ¯uid
reservoir. The ¯uid level
should be above MIN. If it
isn't have your brake
system checked to see if
there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
What to Add
When you do need brake ¯uid, use only DOT-3 brake
¯uid. Use new brake ¯uid from a sealed container
only. See
Part D: Recommended Fluids and Lubricants
on page 6-33.Always clean the brake ¯uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of ¯uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper brake
¯uid.
Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they'll have to be replaced.
Don't let someone put in the wrong kind of ¯uid.
·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
ªAppearance Careº in the Index.
5-38

Brake Wear
If you have four-wheel drive, your vehicle has four-wheel
disc brakes. If not, your vehicle has front disc brakes
and rear drum 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 won't 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.
If you have rear drum brakes, they don't have wear
indicators, but if you ever hear a rear brake rubbing
noise, have the rear brake linings inspected immediately.
Also, the rear brake drums should be removed and
inspected each time the tires are removed for rotation or
changing. When you have the front brake pads
replaced, have the rear brakes inspected, too.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-32.
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.
If you don't have four-wheel drive and your brake pedal
goes down farther than normal, your rear drum
brakes may need adjustment. Adjust them by backing
up and ®rmly applying the brakes a few times.
5-39