1999 CHEVROLET CORVETTE air condition

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LOWER: This setting directs most of the air
through the lower ducts to the floor area of the vehicle
with some of the air also directed toward the windshield
and side window vents.
DEFOG: This setting divides the air between the
windshield and lower outlets with a small amount
directed toward the side window vents. This is useful
when fog appears on the windshield or side glass due to
rain or snowy conditions.
DEFROST: Use this setting to quickly remove fog
or frost from the windshield. This setting directs most of
the airflow to the windshield with a small amount
directed toward the lower and side window outlets.
Mode Buttons
These buttons control the air intake, the air conditioning
and the rear window defogger operation.
FRESH AIR: Press this button and it will bring
outside air into the vehicle. The light on the button will
come on when operating. Use this setting while trying to
defrost or defog windows to help clear moisture.
RECIRCULATE: Press this button to limit the
amount of fresh air entering the vehicle by recirculating
most of the air inside the vehicle. The light on the button
will come on when operating. This setting is helpful
when you are trying to cool the air quickly or to limit
odors entering the vehicle. RECIRCULATE cannot be
used while in the DEFROST or DEFOG modes.
A/C: This button turns the air conditioning
compressor off or on under most conditions. The light
on the A/C button comes on when the compressor is
operating. The air conditioning does not operate at
temperatures below approximately 35
F to 40
F
(2
C to 4
C). The air conditioning cools and
dehumidifies the air coming into the vehicle. The air
conditioning cannot be turned off in DEFROST, as it
helps to remove moisture from the vehicle. It also helps
to keep the windows clear.
The air conditioning may be forced off at high engine
speeds or high engine oil or coolant temperatures.
See ªRear Window Defoggerº later in this section for
more information.

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3-4 Automatic Electronic Dual Climate Control
System (If Equipped)
Your vehicle may be equipped with an Automatic
Electronic Dual Climate Control System. This system
can automatically adjust and control temperature output,
fan speed, air delivery mode, air conditioning operation
and air intake. You can use the AUTO (automatic)
setting or override the automatic operation with
manual control settings. The control settings will be
remembered each time you turn the ignition off
and restart in the same settings. You can use the
memory option to store and recall your settings.
(See ªMemoryº in the Index.)Digital Display
The digital display shows readings in Fahrenheit or
Celsius by pressing the E/M button (English/Metric) on
the Driver Information Center (DIC). When you start
the vehicle, the display will show the current fan speed,
air delivery mode and the driver
-set temperature for
approximately five seconds and then show the
outside temperature.
When the system is fully in the automatic mode, the
word AUTO will also appear on the display. If you have
selected a manual fan speed, then the fan symbol will
appear on the display. If a manual air delivery mode has
been selected, the delivery mode symbol will appear on
the display.
Driver Set Temperature Knob
The DRIVER knob changes the temperature on the
driver's and passenger's side of the vehicle. Turn the
knob clockwise to increase the temperature and
counterclockwise to decrease the temperature.
Whenever you turn this knob, the temperature will be
displayed for approximately five seconds along with the
current fan speed and air delivery mode.

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When adjusting the temperature, start with a driver-set
temperature of 73
F (23
C) until you determine your
comfort zone. If you choose 60
F (16
C), the
system will remain at maximum cooling and will not
automatically adjust fan speed or air delivery. If you
choose 90
F (32
C), the system will remain at
maximum heating and will not automatically adjust fan
speed or air delivery. Choosing either maximum setting
will not cause the system to heat or cool any faster.
Turning the knob past either maximum setting has no
effect on the operation of the system.
Passenger Temperature Offset
The PASSENGER knob changes the temperature on the
passenger's side of the vehicle. When the knob is in the
12 o'clock position, the passenger's temperature is the
same as the driver's. Turn the knob clockwise for
warmer air on the passenger's side, counterclockwise for
cooler air. If the driver
-set temperature is set at 60
F
(16
C) or 90
F (32
C), turning the passenger knob
has no effect because the system is locked at a
maximum setting.Automatic Operation
Press the AUTO button to place the entire system in the
automatic mode. After a five
-second display of the
current settings, only the word AUTO and the outside
temperature will be shown on the digital display. The
system will operate to achieve your comfort set
temperature as quickly as possible. If you have set the
driver temperature at 60
F (16
C) or 90
F (32
C),
the system will not operate automatically until a
different temperature is selected. The AUTO control
system works best with the windows up and the
removable roof installed or the convertible top up.
A Typical Cold Weather Example:
Your vehicle has been parked outside overnight in cold
weather (below 32
F/ 0
C) and you have set the driver
temperature at 73
F (23
C) and have selected the
AUTO mode. The system will automatically adjust the
temperature output to maximum heating. The fan will
start at a low speed. This is to avoid blowing cold air
into the vehicle. The length of the delay depends on the
amount of time since the engine was last started, the
outside temperature and the engine coolant temperature.
As the coolant warms up, the fan speed will gradually
increase. Air will flow to the floor with some air to
the windshield to prevent fogging under most
normal conditions.

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As the interior of the vehicle warms up to your comfort
set temperature, the fan speed will decrease and the
temperature output may become cooler. If the interior
temperature continues to warm up due to heating
from the sun or outside temperature increases, the
system may switch to other air delivery modes
(typically DEFOG or BI
-LEVEL).
A Typical Hot Weather Example:
The vehicle has been parked outside all day in hot
weather (above 70
F/ 21
C) and you have set the driver
temperature at 73
F (23
C) and have selected the
AUTO mode. The system will automatically adjust the
temperature output to maximum cooling. The blower
will start at a low speed momentarily to push the hot air
to the floor of the vehicle and then go to a higher blower
speed with cold airflow out of the instrument panel
outlets. A small amount of airflow will continue through
the lower ducts to cool the floor area.The air intake may start in the recirculated mode for
maximum cooling performance. As the interior of the
vehicle cools down to your comfort set temperature, the
fan speed will decrease and the temperature output may
become warmer. The air intake may shift from
recirculation to fresh air mode. If the interior continues
to cool due to a decrease in the amount of heat the
vehicle is absorbing from the sun or a decrease in the
outside temperature, the system could switch to other air
delivery modes (typically BI
-LEVEL or DEFOG).
Manual Settings
With the Automatic Electronic Dual Climate Control
System, there are several manual settings you can use to
control the system and override the AUTO operation.
You can program the fan speed, air delivery mode, air
intake mode and control the air conditioning operation
using these settings. The system will still determine the
temperature output level based on the driver
-set
temperature and the passenger temperature offset.

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FAN SPEED: Press the button with the fan symbol
on it to manually lock in the current fan speed and to
stop the automatic fan speed control. Pressing the
arrows will delete AUTO from the digital display. The
fan graphics with the fan speed bars will be shown. To
increase the fan speed so that more air flows into the
vehicle, press the UP arrow on the fan switch. To
decrease the fan speed and airflow, press the DOWN
arrow. The AUTO button must be pressed to return to
the automatic fan control.
MODE: Press the MODE button to manually lock in the
current air delivery setting and to stop the automatic
mode control. Pressing the MODE button will delete
AUTO from the digital display and the mode graphics
will be shown. To change the setting, press the MODE
button again. The AUTO button must be pressed to
return to the automatic mode selection.
UPPER: This setting directs most of the air through
the instrument panel outlets and a very small amount to
the lower outlets.
BI-LEVEL: This setting directs air into the
vehicle in two ways. Cooler air is directed toward your
upper body through the instrument panel outlets, while
warmer air is directed through the lower outlets.
LOWER: This setting directs most of the air to the
floor area and some of it toward the windshield and side
window vents.
DEFOG: This setting divides the air between
the windshield and lower outlets and a small amount
toward the side window vents. This is useful when fog
appears on the windshield or side glass due to rain or
snowy conditions.
Mode Buttons
These buttons control climate control ON/OFF, air
intake, front defrost, rear defrost and the air
conditioning operation.
OFF: Press the OFF button to turn off the climate
control system. This is the only setting that fully shuts
off the fan. The digital display will show only the
outside temperature. You can still adjust the driver set
temperature, the passenger temperature offset and the air
intake mode while in OFF.

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A/C: This button turns the air conditioning
compressor on or off, except in the FRONT defrost
mode. The light on the A/C button will come on when
the compressor is operating in either the automatic or
manual mode. The air conditioning may also be forced
off at high engine speeds. The light on the A/C button
will flash if pressed when air conditioning operation is
not allowed.
FRESH AIR: Press this button to provide fresh
air from the outside. The light on this air intake button
will come on to show when it is operating. When in the
AUTO mode, the system automatically selects FRESH
AIR instead of recirculate, as required, to control the
temperature in the vehicle. By pressing FRESH AIR, the
system will lock into the fresh air mode. Any adjustment
to the air intake must then be made manually. FRESH
AIR should be used when trying to defrost or defog
windows to help reduce moisture inside the vehicle.
RECIRCULATE: Press this button to limit the
amount of fresh air entering the vehicle. The light on
this air intake button will come on to show when it is
operating. Recirculate is helpful when you are trying to
cool the air quickly or trying to limit odors and dust
from entering the vehicle. When in the AUTO mode, the
system automatically selects recirculate to cool the
vehicle's temperature. By pressing this button, the
system will lock into the recirculated air mode. Any
adjustment to the air intake must then be made
manually. The recirculated air mode is not allowed in
the front defrost or defog modes as fresh air helps
reduce moisture inside the vehicle.
FRONT: Press the FRONT defrost button to
quickly remove fog or frost from the windshield. This
setting directs most of the airflow to the windshield and
a small amount toward the lower and side window
outlets. The light on the button will come on and the
digital display will show the defrost mode symbol and
fan speed when the front defrost mode is being used.
Pressing FRONT defrost again will return the system to
the last operating mode.

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If the system is in FRONT defrost when you shut the
engine off, it will restart in FRONT defrost unless the
engine is off for longer than 40 minutes. If the engine is
off longer than 40 minutes, the system will restart in the
operating mode you had set prior to FRONT defrost.
The air conditioning cools and dehumidifies air coming
into the vehicle. It also operates in defrost to help
remove moisture from the vehicle. The air conditioning
does not operate at temperatures below approximately
35
F to 40
F (2
C to 4
C). If the system is operating in
the AUTO mode, turning the air conditioning off will
delete AUTO from the digital display and show current
mode and fan settings. The AUTO button must be
pressed to return to the automatic mode operation.
See ªRear Window Defoggerº later in this section for
more information.Sensors
The Automatic Electronic Dual Climate Control
System uses several sensors to control operation and
display information.
Solar Load Sensor
This sensor is located on the top right side of the
defroster grille. The defroster grille is on the top of the
instrument panel.
The sensor monitors the sun's solar radiation and uses
this information as part of the automatic climate control
system when operating in the AUTO mode.
Be careful not to put anything over the sensor. When
covered, the sensor cannot compensate for changes in
the amount of heat the vehicle is absorbing from the sun.

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Outside Air Temperature Sensor
This sensor is located in the air intake under the front
bumper of the vehicle. Information from this sensor
is used for the outside air temperature readings shown
on the digital display for the automatic climate
control system.
If the outside temperature goes up, the displayed
temperature will not change until:

The vehicle's speed is above 20 mph (32 km/h) for
one and a half minutes.

The vehicle's speed is above 45 mph (72 km/h) for
one minute.
These delays help prevent false readings. If the
temperature goes down, the outside temperature display
is updated immediately.
If the vehicle has been turned off for more than three
hours, the current outside temperature will be shown
when you start the vehicle. If it has been turned off for
less than three hours, the temperature will be recalled
from the previous vehicle operation.Inside Temperature Sensor
This sensor is located to the left of the ignition switch.
The automatic climate control system uses this sensor to
receive information, so if you block or cover it, the
system will not function properly.
Air Conditioning
On very hot days, the vehicle will cool down more
quickly and economically if you open the windows long
enough to let hot inside air escape. Then keep the
windows closed in order to allow the air conditioning to
work best. Maximum cooling will occur when the
recirculate setting is operating, airflow direction is in the
upper mode, and the temperature control knob
(on a manual climate control system) is turned all the
way to the blue area. These settings will be selected
by the Automatic Electronic Dual Climate Control
System if operating in AUTO when maximum cooling
is required.
When the air conditioning is on, you may sometimes
notice slight changes in the vehicle's engine
performance and power. This is normal. The system is
designed to help fuel economy while maintaining the
desired cooling level.