1993 GMC SIERRA heater

Comfort Controls & Audio Systems
When you first turn on your vehicle’s air conditioning, open\
the windows to
clear the vehicle of hot air.
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Your system has a lighted display showing each system when it is operating.
During normal operation, all the lights won’t come on at th\
e same time. Only
the ones displaying the current settings will light.
System Controls
NC Button: Press the button marked NC to turn your air conditioner on and
off. The NC symbol will light on your display and air will come out of y\
our
dashboard vents. The fan will automatically be set on
LOW.
When you press the NC 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 selected unless the
OFF button
was pressed.
OFF Button: Press this button to turn the air conditioninglheating \
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 NC, MAX (RECIR on some
models), or one of the
BLEND buttons for the system to come back on.
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).
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Right Button
Defrost (Top): Press here to operate the defroster. Heated air comes out
near the windshield. You can use it to help clear fog or ice on your
windshield.
Heater (Bottom): Press here, and heated air comes out near the floor. This
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.
Left Button
Vent (Top): Press the top of this button and all of the airflow will come
through the instrument panel vents.
Heater (Bottom): Press the bottom of this button and all of the airflow 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 switch 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.
Temperature Selector Bar
The bar under your system display lets you select the temperat\
ure of the air
coming into 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 an arrow moving between
C and H.
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
(t) 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.
Air Recirculation Button
If you press the MAX button (RECIR on some models), 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 vehicle. When
MAX is selected, REC will light on your display.
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Comfort Controls & Audio Systems
i
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. Thes'e a\
re the wires
which heat your window.
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
glass does not get
too hot. If the defogger shuts off, and the window still
isn't clear, turn the defogger on again.
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Run your engine only as long as you musk. This saves fuel. When you run
the engine, make it go a little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the heat that yo\
u get and
it keeps
the battery (or batteries) charged. You will need a well-charged battery (or
batteries) to restart the' vehicle, and possibly for signaling later on with your
headlights. Let the heater run for awhile.
If you 'have a diesel engine, you
may have to run it at a higher speed
to lget enough heat. Then, shut the
engine
off and close the window almost all the way to preserve the heat.
Start the engine again and repeat this only when you feel really
uncomfortable from the cold. But
do it as little as'possible. Preserve the fuel
as long as you can.
To help keep warm, you can get out of the vehicle and
do some fairly vigorous exercises every half hour or so until help comes.
If You're Stuck in Deep Snow
This manual explains how to get the vehicle out of deep snow without
damaging it. See "Rocking Your Vehicle" in the Index.
Towing a mailer
CAUTION I
If you don't use the correct equipment and drive properly, you ca\
n
lose control when you pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well-or even at all. You and your
passengers could be seriously injured. Pull a trailer only if \
you have
followed all the steps in this section.
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Problems on the Road
If your engine catches fire because you keep driving with no cool\
ant, your
vehicle can be bac"lI damaged.
T- ! costly rep; 1 would not be Iverec
by your warranty.
If No Steam Is Coming From Your Engine:
If you get the overheat warning but see or hear no steam, th\
e problem may
not be too serious. Sometimes the engine can get a little too\
hot when you:
Climb a long hill on a hot day.
Stop after high speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam, try t\
his for a minute
or
so:
1. If you have an air conditioner, turn it off.
2. Turn on your heater to full hot at the highest fan speed and\
open the
3. If you're in a traffic jam, shift to N (Neutral).
window as necessary.
If you no longer have the overheat warning, you can drive. Just
to be safe,
drive slower for about ten minutes.
If the warning doesn't come back on, you
can drive normally.
If the warning continues, pull over, stop, and park your vehic\
le right away.
If there's still no sign of steam, push the accelerator until the engine speed is
about twice
as fast as normal idle speed. Bring the engine speed back to
normal idle speed after two or three minutes. Now see if the warning stops.
But then,
if you still have the warning, TURN OFF THE ENGINE AND GET
EVERYONE
OUT OF THE VEHICLE until it cools down.
You may decide not to
lift the hood but to get service help right away.
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The coolant level should be at or above the COLD mark. If it isn’t, you may
have a leak in the radiator hoses, heater hoses, radiator, water pump or
somewhere else in the cooling system.
Heater and radiator hoses, and other engine parts, can be very\
hot.
-, Don’t touch them. If you do, you can be burned.
Don’t run the engine
if there is a leak. If you run the engine, it cou
lose all coolant. That could cause an engine fire, and you could be
burned. Get any leak fixed before you drive the vehicle.
I I
NOTICE
Engine damage from running your engine without coolant isn’t covered by
I your warranty.
If there seems to be no leak, check to see if the electric engine fan (if you
have one) is running.
If the engine is overheating, the fan should be running.
If it isn’t, your vehicle needs service.
Start the engine again to see
if the regular fan runs when the engine does.
If it doesn’t, your vehicle needs service. Turn off the engine.
How to Add Coolant to the Coolant Recovery Tank
If you haven’t found a problem yet, but the coolant level isn’t at or above
COLD, add a 50hO mixture of clean water (preferably distilled) and a proper
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Service & Appearance Care
Engine Block Heater:
An engine block heater can be a big help if you have to park outside in very
cold weather,
0°F (-18°C) or colder. If your vehicle has this option, see
“Engine Block Heater” in the Index.
What to Do with Used Oil:
I CAUTION I
Used engine oil contains things that have caused skin cancer
laboratory animals. Don’t let used oil stay on your skin fo\
r very
I
Clean your skin and nails with soap and water, or a good han\
d
cleaner. Wash or properly throw away clothing or rags containin\
g
used engine oil.
Used-oil can be a real threat
to the environment. If you change your own oil,
be sure to drain all free-flowing oil from the filter before disp\
osal. Don’t ever
dispose of oil by putting it in the trash, pouring it on the ground, into sewers,
or into streams or bodies of water. Instead, recycle it by taking it to a place
that collects used
oil. If you have a problem properly disposing of your used
oil, ask your dealer, a service station or a local recycling \
center for help.
Engine Oil (Diesel Engines)
It’s a good idea to check your engine oil level 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.
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Turn off the engine and give the oil a few minutes to drain back into the oil
pan. If you don’t the
oil dipstick might not show the actual level.
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1 CAUTION
4 Adding only plain water to your cooling system can be dangerous.
Plain water, or some other liquid like alcohol, can boil before th(
)per coolant mix will. Your vehicle’s coolant warning system is set
for the proper coolant mix. With plain water or the wrong mix\
, your
engine could get too hot but you wouldn’t get the overheat warning.
Your engine could catch fire and you or others could be burned. Use
a
50/50 mix of clean water and a proper antifreeze.
NOTICE
If you use an improper coolant mix, your engine could overheat an\
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badly damaged. The repair cost wouldn’t be covered by your warranty. 1
much water in the mix can freeze and xk +?e t line radiator, heater
core and other parts.
Some conditions, such as air trapped in the cooling system, can affect the
coolant level in the radiator. Check the coolant level when the engine is cold
and follow the steps under “Adding Coolant” for the prope\
r way to add
coolant.
If you have the low coolant warning system, refer to the General Motors
Service Manual or see your dealer for the proper coolant
fill procedure. (To
purchase a Service Manual, see “Service Publications’’ in the Index.) Using
the wrong
fill procedure can cause a low coolant warning indication.
If you have to add coolant more than four times a year, have your dealer
check your cooling system.
If you use the proper coolant, you don’t have to add extra inhibitors or
additives which claim to improve
the system. These can be harmful.
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NOTICE .I
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