heating GMC SONOMA 2000 Owner's Manual

Table of Contents (cont'd)
Braking/Anti-lock Brakes (If Equipped)
Traction Control System
Steering
Driving Tips for Various Road ConditionsOff-Road Driving
Recreational Vehicle Towing
Loading Your Vehicle
Towing a Trailer Heating and Air Conditioning
Setting the Radio Clock
Radio/Cassette Player/CD PlayerRadio Theft-Deterrent Feature
Steering Wheel Controls (If Equipped)
Hazard Warning Flashers
Jump Starting
Towing Your VehicleEngine Overheating
Changing a Flat Tire
If You're Stuck
Problems on the Road
Section
3
Section
4
Section
5
Your Driving and the Road Comfort Controls and Audio Systems
iii

2-49
NOTICE:
Don't hold a cigarette lighter in with your hand
while it is heating. If you do, it won't be able to
back away from the heating element when it's
ready. That can make it overload, damaging the
lighter and the heating element.
Sun Visors
To block out glare, you can swing down the sun visor.
You can also swing the visor from side to side.
Visor Vanity Mirror
Pull the sun visor down and lift the cover to expose the
vanity mirror.
Illuminated Visor Vanity Mirror
(If Equipped)
Pull the sun visor down and lift the mirror cover to turn
on the lamps.
Accessory Power Outlets
(If Equipped)
If you have accessory power outlets, you can plug in
auxiliary electrical equipment. The accessory power
outlets are located near the center of the vehicle on the
lower part of the instrument panel. Just remove the
plug from the outlet and follow the proper installation
instructions that are included with any electrical
equipment you install.
These circuits are protected by a fuse and have
maximum current levels.
NOTICE:
When using the accessory power outlets,
maximum electrical load must not exceed
20 amps. Always turn off any electrical
equipment when not in use. Leaving electrical
equipment on for extended periods will drain
your battery.

2-60 Anti-Lock Brake System Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on
for several seconds.
That's normal.
If the light stays on, or comes on when you're driving,
your vehicle needs service. If the regular brake system
warning light isn't on, you still have brakes, but you
don't have anti
-lock brakes. If the regular brake system
warning light is also on, you don't have anti
-lock brakes
and there's a problem with your regular brakes. See
ªBrake System Warning Lightº earlier in this section.
The anti
-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature.
If the gage pointer moves into the red area, your engine
is too hot!
It means that your engine coolant has overheated. If you
have been operating your vehicle under normal driving
conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
The ªProblems on the Roadº section of this manual
shows you what to do. See ªEngine Overheatingº in
the Index.

3-
3-1
Section 3 Comfort Controls and Audio Systems
In this section, you'll find out how to operate the comfort control and audio systems offered with your vehicle.
Be sure to read about the particular systems supplied with your vehicle.
3
-2 Comfort Controls
3
-2 Standard Climate Control System
3
-3 Optional Climate Control System
3
-4 Air Conditioning (If Equipped)
3
-4 Heating
3
-5 Defogging and Defrosting
3
-5 Ventilation System
3
-6 Audio Systems
3
-6 Setting the Clock for Systems
with SET Button
3
-6 Setting the Clock for Systems
with HR and MN Buttons
3
-7AM-FM Stereo3
-9AM-FM Stereo with Cassette Tape
Player (If Equipped)
3
-12 AM-FM Stereo with Cassette Tape Player and
Automatic Tone Control (If Equipped)
3
-16 AM-FM Stereo with Compact Disc Player and
Automatic Tone Control (If Equipped)
3
-20 Remote Cassette Tape Player (If Equipped)
3
-22 Theft-Deterrent Feature (If Equipped)
3
-24 Understanding Radio Reception
3
-24 Tips About Your Audio System
3
-25 Care of Your Cassette Tape Player
3
-26 Care of Your Compact Discs
3
-26 Care of Your Compact Disc Player
3
-26 Fixed Mast Antenna

3-2
Comfort Controls
With these systems, you can control the heating, cooling
and ventilation in your vehicle.
Standard Climate Control System
Fan Control
The knob on the left side of the heating system control panel
controls the fan speed. To increase airflow, turn the knob
clockwise. To decrease airflow, turn it counterclockwise.
Temperature Knob
The middle knob on the control panel lets you select
the relative temperature of the air flowing into the
passenger area of your vehicle. Turn the knob clockwise
toward the red area for warmer air. Turn the knob
counterclockwise toward the blue area for cooler air.Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
OFF: This setting turns the system off. Some outside
air will still enter the vehicle whenever the vehicle is
moving forward.
VENT: This setting directs most of the air through
the instrument panel outlets and a small amount through
the floor outlets.
BI-LEVEL: Air is delivered through the heater
floor outlets as well as the instrument panel outlets.
HEATER: This setting directs most of the
warmed air through the heater floor outlets and some
air through the windshield defroster outlets.
BLEND: Airflow is divided equally between the
heater floor outlet and the windshield defroster outlets.
DEFROST: This setting directs most air through
the windshield defroster outlets and some through the
heater outlets.

3-3 Optional Climate Control System
Fan Control
The knob on the left side of the heating system
control panel controls the fan speed. To increase airflow,
turn the knob clockwise. To decrease airflow, turn
it counterclockwise.
Temperature Knob
The middle knob on the control panel lets you select
the relative temperature of the air flowing into the
passenger area of your vehicle. Turn the knob clockwise
toward the red area for warmer air. Turn the knob
counterclockwise toward the blue area for cooler air.Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
OFF: This setting turns the system off. Some outside
air will still enter the vehicle whenever the vehicle is
moving forward.
MAX A/C: This setting provides maximum cooling
with the least amount of work. MAX A/C recirculates
much of the air inside your vehicle so it cools quickly.
This setting directs most of the air through the
instrument panel vents and a small amount through
the floor vents.
A/C: This setting cools the air entering your vehicle and
directs most of the air through the instrument panel
vents and a small amount through the floor vents.
BI-LEVEL A/C: This setting cools the air
entering your vehicle and directs it through the heater
floor outlets as well as the instrument panel outlets.
VENT: This setting directs most of the air through
the instrument panel outlets and a small amount through
the floor outlets. The air conditioning compressor is not
working when VENT is selected.

3-4
HEATER: This setting directs most of the
warmed air through the heater floor outlets and some air
through the windshield defroster outlets.
BLEND: Airflow is divided equally between the
heater floor outlet and the windshield defroster outlets.
DEFROST: This setting directs most air through
the windshield defroster outlets and some through the
heater outlets.
Air Conditioning (If Equipped)
On hot days, open the windows long enough to let hot
inside air escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
For quick cool
-down on very hot days, use MAX A/C
with the temperature knob turned counterclockwise.
This setting should be used to keep odors and/or dust
from entering the vehicle. For normal cooling on
hot days, use A/C with the temperature knob
turned counterclockwise.On cool but sunny days, use BI
-LEVEL A/C to deliver
warm air to the floor and cooler air to the instrument
panel outlets.
If you have the VORTEC 4300 V6 engine, when the
air conditioner is on, you may sometimes notice slight
changes in your vehicle's engine speed and power. This
is normal because the system is designed to cycle the
compressor on and off to keep the desired temperature.
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use HEATER with the
temperature knob turned clockwise. BLEND is useful in
cool weather when you have fog or ice on the
windshield or side windows.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See ªEngine Coolant Heaterº in the Index.

3-5 Defogging and Defrosting
On cool, humid days, use BLEND to keep the
windshield and side windows clear.
Use DEFROST to remove fog or ice from the
windshield quickly in extreme humid or cold conditions.
Turn the temperature knob clockwise and turn the fan
control toward high.
If you have the heated outside mirror feature, you can
use it to defog or defrost your outside mirrors. For more
information, see ªHeated Outside Mirrorsº in the Index.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Airflow is through the instrument
panel outlets.
Your vehicle's ventilation system supplies outside air to
the inside of your vehicle when it is moving. When the
vehicle is not moving, you can get outside air to flow
through by selecting any mode and any fan speed.
You will find air outlets in the center and on the sides of
your instrument panel.
You can direct the airflow side
-to-side by moving the
thumbwheel located in the center of the vent. The vent
can be tilted up and down also. To control the amount
of airflow through the outlets, move the thumbwheel
below the vent.

4-53
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine off.
If you do get the overheat warning, see ªEngine
Overheatingº in the Index.
Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet, or into gear for a manual
transmission. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P), or
REVERSE (R) for a manual transmission.
5. Release the regular brakes.

5-
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
-2 Other Warning Devices
5
-3 Jump Starting
5
-7 Towing Your Vehicle
5
-8 Engine Overheating
5
-9 Cooling System5
-18 Engine Fan Noise
5
-18 If a Tire Goes Flat
5
-19 Changing a Flat Tire
5
-30 Compact Spare Tire (If Equipped)
5
-31 If You're Stuck: In Sand, Mud, Ice or Snow