2001 CHEVROLET C3500 HD Owners Manual

2-56
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused by
a dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon
as possible.
Security Light
This light will come on
briefly when you turn the
key to START.
The light will come on for five seconds after the key is
turned to ON and then go off. If the light flashes, the
Passlock

System has entered a tamper mode. If the
vehicle fails to start, see ªPasslockº in the Index.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
System. Your vehicle will not be protected by Passlock,
and you should see your GM dealer.

2-57 Up Shift Light (If Equipped)
This light is used on models
with manual transmissions.
The SHIFT indicator light will help you get the best fuel
economy. See ªShift Lightº or ªShift Speedsº in this
section for more information.
Daytime Running Lamps Indicator Light
This light goes on whenever
the DRL are on.
When it begins to get dark, the DRL indicator light
comes on as a reminder to turn on your headlamps.
Check Gages Light
This light will come on
briefly when you are
starting the engine.
If the light comes on and stays on while you are driving,
it could indicate a problem with your vehicle. It could be
a problem with your oil pressure, coolant temperature,
or some other problem. Check your various gages to see
if they are in the warning zones. If they are, have your
vehicle serviced right away.

2-58 Fuel Gage
United States Canada
The fuel gage, when the ignition is on, tells you about
how much fuel you have left in your tank.The gage will first indicate empty before you are out of
fuel, and you should get more fuel as soon as possible.
Here are four situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.

At the gas station, the fuel pump shuts off before the
gage reads full.

It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.

The gage moves a little when you turn a corner or
speed up.

The gage doesn't go back to empty when you turn
off the ignition.
If you have a diesel engine, see ªFuel Gageº in the
Diesel Engine Supplement.

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
-4 Air Conditioning
3
-4 Heating
3
-4 Defogging and Defrosting
3
-5 Ventilation System
3
-6 Audio Systems
3
-6 Setting the Clock3
-7AM-FM Stereo
3
-9AM-FM Stereo with Cassette Tape Player
(If Equipped)
3
-12 Understanding Radio Reception
3
-12 Tips About Your Audio System
3
-13 Care of Your Cassette Tape Player
3
-14 Fixed Mast Antenna

3-2
Comfort Controls
Heater Control System
Fan Knob
The knob located on the left side of the heating system
control panel regulates the fan speed. The knob has
four speed positions. To increase airflow, turn the knob
toward HI. To decrease airflow, turn it toward LO.
To turn the fan off, turn the knob to OFF.Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing into the passenger area of
your vehicle. This knob will allow you to adjust the air
temperature independently of the fan knob settings. 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. The knob can be
placed in any position between two mode settings to
blend the flow of air.
VENT: This setting directs air through the
instrument panel outlets.
BI-LEVEL: This setting divides airflow between
the floor outlets and instrument panel outlets.
HEATER: This setting directs air through the
floor outlets.
BLEND: This setting directs air to the heater
outlets and toward the windshield.
DEFROST: This setting directs air toward
the windshield.

3-3 Heater and Air Conditioning Control
System (If Equipped)
Fan Knob
The knob located on the left side of the heating system
control panel regulates the fan speed. The knob has
four speed positions. To increase airflow, turn the knob
toward HI. To decrease airflow, turn it toward LO. To
turn the fan off, turn the knob to OFF. If you have the air
conditioner on, turning the fan knob to OFF also turns
off the A/C compressor.
With the fan knob in OFF while driving, the airflow will
be directed to the floor air outlets. The mode knob will
not redirect airflow to other selected outlet positions.
This is normal operation for OFF.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. This knob will allow you to adjust
the relative air temperature independently of the fan and
knob settings. 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. The knob can be placed in any
position between two mode settings to blend the flow of air. VENT: This setting directs air through the
instrument panel outlets.
BI-LEVEL: This setting divides airflow between
the floor air outlets and instrument panel air outlets.
HEATER: This setting directs air through the
heater floor air outlets.
BLEND: This setting directs air to the heater air
outlets and toward the windshield.
DEFROST: This setting directs air toward
the windshield.

3-4 Air Conditioning
On hot days, open the windows long enough to let hot
air inside 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.
A/C: Press this button to turn the air conditioning on
and off. The system will cool and dehumidify the air
inside the vehicle when the A/C light is on.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which air
conditioning is ineffective.
With the A/C on, turn the temperature knob to MAX for
maximum cooling. This setting also puts the system in
the recirculation mode and helps to maximize your air
conditioner's performance and your vehicle's fuel economy.
RECIRCULATION: Pressing the
RECIRCULATION button limits the amount of outside
dust and odors entering your vehicle. This button will be
automatically disabled anytime the mode knob is turned to
BLEND or DEFROST mode. (The recirculation indicator
light will come on even though the recirculation button is
not selected). This setting also cools the air the fastest.
After the vehicle's interior reaches a comfortable
temperature, turn the temperature knob clockwise, to
place the air conditioning system in the normal mode.
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the HEATER or BI
-LEVEL
setting with the temperature knob in the red area.
If you use the engine coolant heater before starting your
engine in cold weather, 20
F (
-8
C) or lower, your
heating system will produce warmer air faster, to heat
the passenger compartment in cold weather.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature, and shortens the time it takes the heater to
reach full output. For more information, see
ªEngine Coolant Heaterº in the Index.
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 in extremely humid or cold
conditions. Use DEFROST with the temperature knob
toward the red area and the fan control toward HI.

3-5 Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Air will flow through the
instrument panel outlets.
Your vehicle's ventilation system supplies outside air to
the inside of your vehicle when it is moving. With the side
windows closed, air will flow into the front air inlet grilles,
through the vehicle, and out the air exhaust valves.
Outside air will also enter the vehicle when the heater or
the air conditioning fan is running, unless you have the
recirculation button pushed in. For more information on
the recirculation button, see ªAir Conditioningº earlier
in this section.
Your vehicle has air outlets in the center and on the sides
of your instrument panel. You can move the outlets from
side
-to-side or up and down to direct the flow of air, or
close the outlets altogether. When you close an outlet, it
will increase the flow of air coming out of any outlets
that are open. These outlets do not completely shut off
airflow when in the closed position.