1999 CHEVROLET SILVERADO towing

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Basic Trailer Wiring Package (Diesel Engine)
Regular and extended cab pickups equipped with a
6.5L Turbo Diesel engine have an eight
-wire trailer
towing harness.
The trailer wiring harness with a seven-pin connector
and separate Center High
-Mounted Stoplamp (CHMSL)
connector are located at the rear of the vehicle and are
tied to the vehicle's frame.* The harness connector can
be plugged into a seven
-pin universal heavy-duty trailer
connector available through your GM dealer.* The single CHMSL wire is tied to the seven
-wire
harness and is used if your trailer or cap are equipped
with a CHMSL.
The eight
-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: CHMSL

Red: Battery Feed

Dark Blue: Trailer Brake
If you need to upgrade your vehicle to heavy
-duty
trailering, a brake controller harness and a seven
-pin
universal heavy
-duty trailer connector are available
from your GM dealer.

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Heavy-Duty Trailer Wiring Package (If Equipped)
Your pickup may be equipped with the eight-wire trailer
towing harness. This harness with a seven
-pin universal
heavy
-duty trailer connector is attached to a bracket on
the platform hitch.*
* The Center High
-Mounted Stoplamp (CHMSL) wire
is tied next to the trailer wiring harness for use with a
trailer, slide
-in camper or cap.The eight
-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: CHMSL

Red: Battery Feed

Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake controller
and a trailer battery feed fuse are included with this
trailering package. (See ªInstrument Panel Jumper
Wiring Harnessº later in this section.)
If you need to tow a light
-duty trailer with a standard
four
-way round pin connector, an adapter connector is
available from your dealer.

5-
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5-1
Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-3 Other Warning Devices
5
-3 Jump Starting
5
-8 Towing Your Vehicle
5
-9 Engine Overheating (Gasoline Engine)5
-12 Cooling System (Gasoline Engine)
5
-18 Engine Fan Noise
5
-18 If a Tire Goes Flat
5
-18 Changing a Flat Tire
5
-33 If You're Stuck: In Sand, Mud, Ice or Snow

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5-8
Towing Your Vehicle
CAUTION:
To help avoid serious personal injury to you
or others:

Never let passengers ride in a vehicle that is
being towed.

Never tow faster than safe or posted speeds.

Never tow with damaged parts not
fully secured.

Never get under your vehicle after it has
been lifted by the tow truck.

Always secure the vehicle on each side with
separate safety chains when towing it.

Use only the correct hooks.
NOTICE:
Use the proper towing equipment to avoid
damage to the bumper, fascia or fog lamp areas
of the vehicle.
With current trends in automotive styles and design, it is
essential that the correct towing equipment is used to
tow a vehicle. Your vehicle can be towed with wheel lift
equipment or car carrier equipment. Two
-Wheel-Drive
vehicle towing limits for wheel lift equipment:

Front Towing
-- 35 mph (55 km/h) for
50 miles (80 km)

Rear Towing
-- 55 mph (88 km/h) or legal speed limit
and the distance is unlimited.
Four
-Wheel-Drive vehicles must have the transfer case
in NEUTRAL (N). See ªFour
-Wheel Driveº in the
Index for the proper procedure to select the neutral
position for your vehicle. The towing limits for
Four-Wheel-Drive vehicles with wheel lift equipment:

Front Towing
-- 55 mph (88 km/h) or legal speed
limit and distance is unlimited

Rear Towing
-- 55 mph (88 km/h) for
50 miles (80 km).
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº in the Index.

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Engine Overheating
(Gasoline Engine)
You will find a coolant temperature gage on your
vehicle's instrument panel. See ªEngine Coolant
Temperature Gageº in the Index. In addition, you will
find a LOW COOLANT, CHECK COOLANT TEMP,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the message center on the
instrument panel. See ªMessage Centerº in the Index.
If your vehicle has a diesel engine, see ªEngine
Overheatingº in the Diesel Engine Supplement.
Overheated Engine Protection Operating
Mode (V8 Gasoline Engines Only)
Should an overheated engine condition exist and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing groups
of cylinders helps prevent engine damage. In this mode,
you will notice a loss in power and engine performance.
This operating mode allows your vehicle to be driven to
a safe place in an emergency. Towing a trailer in the
overheat protection mode should be avoided.
NOTICE:
After driving in the overheated engine protection
operating mode, to avoid engine damage, allow the
engine to cool before attempting any repair. The
engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the
oil life monitor. See ªEngine Oilº in the Index.

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Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan speed
increases as the clutch more fully engages. So you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional
cooling is not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a ªblowout,º here are a few
tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you'd use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
-- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your hazard
warning flashers.

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If You're Stuck: In Sand, Mud,
Ice or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you don't want to spin your
wheels too fast. The method known as ªrockingº can
help you get out when you're stuck, but you must
use caution.
CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured. And,
the transmission or other parts of the vehicle can
overheat. That could cause an engine
compartment fire or other damage. When you're
stuck, spin the wheels as little as possible. Don't
spin the wheels above 35 mph (55 km/h) as shown
on the speedometer.
NOTICE:
Spinning your wheels can destroy parts of your
vehicle as well as the tires. If you spin the wheels
too fast while shifting your transmission back
and forth, you can destroy your transmission.
For information about using tire chains on your vehicle,
see ªTire Chainsº in the Index.
Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will clear
the area around your front wheels. If you have a four
-wheel
drive vehicle, shift into 4HI. Then shift back and forth
between REVERSE (R) and a forward gear (or with a
manual transmission, between FIRST (1) or SECOND (2)
and REVERSE (R)), spinning the wheels as little as possible.
Release the accelerator pedal while you shift, and press
lightly on the accelerator pedal when the transmission is in
gear. By slowly spinning your wheels in the forward and
reverse directions, you will cause a rocking motion that may
free your vehicle. If that doesn't get you out after a few tries,
you may need to be towed out. Or, you can use your recovery
hooks if your vehicle has them. If you do need to be towed
out, see ªTowing Your Vehicleº in the Index.

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3. Remove the air filter by pulling downward on the
element. Remove the second portion of the air filter
by sliding it towards the rear of the vehicle and then
pulling downward.
4. Install the new filter by reversing the steps listed
previously. Be sure to follow any instructions that
may be included in the replacement filter package.
Refer to the Maintenance Schedule to determine when to
replace the passenger compartment air filter. See
ªScheduled Maintenanceº in the Index.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see ªAutomatic
Transmission Fluidº in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.
When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading on
the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Be sure to get an accurate reading if you check
your transmission fluid.