1994 GMC SIERRA Owners Manual

Air Vents
If your vehicle does not have air conditioning, there are air vents be\
low the
instrument panel.
- Use the handles below
your steering wheel,
with the vent symbols
on them, to open and
close the vents.
If your vehicle has air
conditioning, you will
find air vents in the center and on the sides
of your instrument
panel.
You can move the vents grilles from side to side or up and down to direct
the flow of air,
or close the vents altogether.
When you close a vent, it will increase the flow of air coming out of any
vents that are open.
3-3
ProCarManuals.com

Heater Output
Engine Coolant Heater (Engine Block Heater)
If your vehicle has a diesel engine, it is equipped with an engine coolant
heater. An engine coolant heater
is optional on gas engine vehicles. You can
use an engine coolant heater during initial start-up
in cold weather (20” F,
-8” C, or lower) to help heat the passenger compartment faster. Because an
engine coolant heater warms the engine coolant, your vehicle’s heating
system can provide some heat
as soon as you start the engine.
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 “Engine Coolant
Heater”
in the Index.
Diesel Engine
If you idle your diesel engine for a long time when it’s cold outside, your
heater may blow out cool air. This
is normal. When you increase the engine
speed, your heater should blow
out warmer air. If it doesn’t, your coolant
level may be low. See “Engine Coolant”
in the Index to find out how to
check your coolant level.
3-4
ProCarManuals.com

Weating System (Without Air Conditioning)
If your vehicle does not have air conditioning, this is what your heating
system
will look like.
Function Le wer
The upper lever on the control panel can be moved to three different heating
functions.
0
0
0
Vent (Left): Air comes out at the vents on your instrument panel and at
your front side windows.
Heater (Center): Air comes out near the floor. This setting, along
with a heat setting, is best for cold weather.
Defrost (Right): This setting operates the defroster. Air comes out
near the bottom of the windshield and at your front side windows. Use
this setting, along
with a heat setting, when you get fog or ice on the
windshield.
Placing the lever between positions sends air out both vents.
Temperature Le wer
The lower lever on the control panel lets you select the temperature of the
air flowing into the passenger area
of your vehicle. Move the lever right
toward
“+” for warmer air. Move the lever left toward “-” for cooler air.
Fan Control Knob
The knob on the right side of the heating system control panel controls the
fan speed. The knob has four speed positions. To increase the air flow, turn
the knob toward
“+”. To decrease the air flow, turn it toward “-”.
3-5
ProCarManuals.com

Electronic Heating/Air Conditioning System
If your vehicle has air conditioning, your heating/air conditioning system
will look like this.
When
you first turn on your vehicle’s air conditioning, open the windows to
clear the vehicle of hot air. Using the
MAX button can also help. See
“MAX Button” in this section for more information.
Function Display
Your system has a lighted display showing each system when it is operating.
During normal operation, all the lights won’t come
on at the same time.
Only the ones displaying the current settings will
light.
3-6
ProCarManuals.com

Temperature Selector Bar
The bar under your system display lets you select the temperature of the air
flowing into the passenger area
of your vehicle. Press COLD for cooler air
and press
HOT for warmer air. Release the bar when the system reaches the
temperature you want. The temperature is shown on
the display by the
arrow moving between
C and H.
Air Controls (BLEND)
The two buttons to the right of the system display control the air flow. You
can blend the air flow to suit your needs. The amount
of blending is shown
on the display by an arrow moving between the figure’s feet (floor air flow)
and head (vent air flow).
Left Button
Vent (Top): Press the top of this button and the air flow will come through
the instrument panel vents.
Heater (Bottom): Press the bottom of this button and the air flow will come
through the floor outlet.
The air flow can be blended between the two positions. To blend between
positions press the side of
the button showing the area where you would like
more air flow. The system will automatically begin to blend toward the
position chosen. To stop the system between positions, just press the
SAME
side of the button again.
Right Button
Defrost (Top): This setting operates the defroster. Air comes out near the
bottom
of the windshield and at your front side windows. Use this setting,
along
with a heat setting, when you get fog or ice on the windshield.
Heater (Bottom): Press the bottom of this button and air comes out near the
floor. This setting, along with
a heat setting, is best for passenger comfort in
cold weather.
The air flow can be blended between
the two positions. To blend between
positions, press the side
of the button showing the area where you would
like more air flow. The system
will automatically begin to blend toward the
position chosen. To stop the system between positions, just press the
SAME
side of the button again.
3-7
ProCarManuals.com

A/C Button
Press the button marked A/C to turn your air conditioner on and off. The
A/C symbol will light on your display and air will come out of your
instrument panel vents. The fan
will automatically be set on LOW.
When you press the A/C button to turn the air conditioner off, the system
will operate in the
vent mode. When you turn the air conditioner back on,
the system will operate
in the mode that you last selectcd unless the OFF
button was pressed.
MAX Button
If you press the MAX button, the air in your vehicle will be recirculated.
With the air conditioner on,
MAX will give you maximum cooling. It can
also be used
in all modes to help keep dust out of your vchicle. When MAX
is selected, REC will light on your display.
If your air conditioner develops high system pressure, it will automatically
go into the
MAX mode and REC will light on your display. The A/C
system will remain in the MAX mode, even if you press the MAX button,
until system pressure returns
to a normal level.
Fan Control Button
This button is in the upper right corner of your system control panel. The
fan has four settings
- low, medium low, medium high and high. Press the
top of the button
“+” to increase the air flow. Press the bottom of the button
“-” to decrease the air flow. The setting you select is shown on your display
as LOW, MED LOW, MED HI or HI.
OFF Button
Press this button to turn the air conditioning/heating system off. Pressing
OFF will erase the present mode of operation from the system’s memory.
Outside air will still come out of
the heater outlet whenever the vehicle is
moving forward.
If the OFF button was pressed, you must press A/C, MAX, or one of the
BLEND buttons for the system to come back on.
Rear Window Defogger
You can tell if your vehicle has this option by looking at the rear window. If
you see lines running across the glass, you have it. These are the conductive
wire-like elements which heat your window.
3-8
ProCarManuals.com

I NOTICE:
Scraping the inside of your rear window could cut and damage
the defogger. Your warranty would not cover this damage. And,
don’t put decals there, you might have to scrape them
off.
For best results, clear the window of as much snow or ice as possible first.
To turn on the rear
window defogger, find
the switch marked
REAR DEFOG on
your instrument panel,
just below the heater
system. Press the right
side
of the switch,
with the defog symbol
on it,
until the light in
the switch comes on,
then release
it.
The rear window defogger will only work if the ignition switch is turned to
RUN.
You can turn the defogger off at any time by pressing the left, lighted side of
the switch. The defogger will shut itself off after several minutes, so that the
isn’t clear, turn
the defogger on again.
a olass does not get too hot. If the defogger shuts off, and the window still
Audio Systems
Your Delco@ audio system has been designed to operate easily and give
years of listening pleasure.
You will get the. most enjoyment out of it if you
acquaint yourself with
it first. Find out what your Delco@ system can do
and
how to operate all its controls, to be sure you’re getting the most out of
the advanced engineering that went into
it.
Be aware that hearing damage from loud noise is almost undetectable until
it is too late. Your hearing can adapt to higher volumes of sound. Sound that
seems normal can be loud and harmful
I:O your hearing. Take precautions by
adjusting the volume control
on your radio to a safe sound level before your
hearing adapts to it.
To help avoid hearing loss or damage:
0 Adjust the volume control to the lowest setting.
Increase volume slowly until you hear comfortably and clearly.
3-9
ProCarManuals.com

FM Stereo
FM stereo will give you the best sound. But FM signals can only reach
about
10 to 40 miles (16 to 65 km). And, tall buildings or hills can interfere
with
FM signals, causing the sound to come and go.
AM
The range for most AM stations is greater than for FM, especially at night.
The longer range, however, can cause stations to interfere
with each other.
AM
can pick up noise from things like electrical storms and power lines. If
the noise interferes with your listening, try reducing the treble to lessen the
noise.
AM Stereo
This means the Delco@ system can receive C-QUAM@ stereo broadcasts.
Many AM stations around
the country use C-QUAM@ to produce stereo,
though some
do not. If your Delco@ system can get C-QUAM@, your
“STEREO” light will come on when you’re receiving it. (C-QUAM’ is a
registered trademark of Motorola, Inc.).
NOTICE:
Before you add any sound equipment to your vehicle - like a
tape player, CB radio, mobile telephone or two-way radio - be
sure you can add what you want. If you can,
it’s very important
to do it properly. Added sound equipment may interfere with the
operation
of your vehicle’s engine, Delco@ radio or other
systems, and even damage them. And, your vehicle’s systems
may interfere with the operation of sound equipment that has
been added improperly.
So, before adding sound equipment, check with your dealer and
be sure to check Federal rules covering mobile radio and
telephone units.
3-10
ProCarManuals.com