2004 GMC YUKON air condition

Be careful not to cover the sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun
load, and also turns on your headlamps.
To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is
available. The length of delay depends on the engine
coolant temperature. Pressing the fan switch will
override this delay and change the fan to a selected
speed.
9(Off):Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle, and
will be directed to the oor. This direction can be changed
by pressing the mode button. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is off.
Manual Operation
You may manually adjust the air delivery mode or fan
speed.
w9x(Fan):The switch with the fan symbol allows
you to manually adjust the fan speed. Press the up
arrow to increase fan speed and the down arrow
to decrease fan speed.
Pressing this button when the system is off will turn the
system on.
C(Mode):Press this button to manually change the
direction of the airow in your vehicle; keep pressing the
button until the desired mode appears on the display.
If you press the mode button to select an air delivery
mode, the display will change to show you the selected
air mode delivery. The display will then show the current
status of the system. When the system is turned off, the
display will go blank after displaying the current status of
the system.
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H(Panel):This setting will deliver air to the
instrument panel outlets.
)(Bi-Level):This setting will deliver warmer air to the
oor and cooler air to the instrument panel outlets.
6(Floor):This setting will deliver air to the oor
outlets.
-(Defog):See “Defogging and Defrosting” later in
this section.
@(Recirculation):Press this button to limit the
amount of outside air entering your vehicle. The light on
the recirculation button will glow. This is helpful when you
are trying to limit odors entering your vehicle and for
maximum air conditioning performance in hot weather.
Press this button again to allow outside air to enter the
vehicle. The light on the recirculation button will go off.
Pressing this button also cancels the auto recirculation
feature. To resume the auto recirculation function, press
the AUTO button. Each time the vehicle is started, the
system will revert to the auto recirculation function.If you select recirculation while in defrost, defog or oor,
the light in the button will ash and then go out to let you
know that this is not allowed. This is normal and helps to
prevent fogging.
When the weather is cool or damp, operating the system
in recirculation for extended periods of time may cause
fogging of the vehicle’s windows. To clear the fog, select
either defog or front defrost.
You may also notice that the A/C compressor will run
while in recirculation mode. This is normal and helps to
prevent fogging.9(Off):Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle, and
will be directed to the oor. This direction can be changed
by pressing the mode button. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is off.
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Display
If you press the MODE button to select an air delivery
mode, the display will change to show you the selected
air delivery mode. After ten seconds, the display will
change to show the driver temperature setting and the
selected mode.
If you press the up or down arrows on the fan switch,
the display will change to show the selected fan speed.
After ten seconds, the display will change to show
the driver temperature setting and the selected mode.
Whenever you press AUTO, the display will change
to show the following:
The current driver’s set temperature and an arrow
for ve seconds
The current passenger’s set temperature setting
and an arrow for ve seconds
The automatic air delivery mode and fan speed
If the driver’s and passenger’s temperature settings are
the same when AUTO is pressed, the temperature
setting and both arrows will be displayed for ve
seconds along with the automatic air delivery mode and
fan speed. After the ve second update, the display
will change to show the temperature setting, both arrows
and AUTO.
Air Conditioning
#
(Air Conditioning):Press this button to turn the air
conditioning (A/C) compressor on and off. The snowake
symbol will appear on the display when the A/C is on.
Pressing this button when the outside temperature is too
cool for air conditioning will make the snowake symbol
ash three times and then turn off to let you know the air
conditioning mode is not available. If the air conditioning
is on and the outside temperature drops below a
temperature which is too cool for air conditioning to be
effective, the snowake symbol will turn off to let you
know the air conditioning mode has been canceled.
^(Air Conditioning Off):On some vehicles, when
you turn the air conditioning off, this symbol will appear
on the display. If your vehicle does not have this
symbol, the snowake symbol will turn off to let you
know the air conditioning is off.
When air conditioning is selected or in AUTO mode, the
system will run the air conditioning automatically to cool
and dehumidify the air entering the vehicle. If you select
A/C off while in front defrost, defog or recirculation, the
A/C snowake symbol will turn off, but the A/C
compressor will still run to help prevent fogging.
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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.
On cool, but sunny days while using manual operation
of the automatic system, use bi-level to deliver warm
air to the oor and cooler air to the instrument
panel outlets. To warm or cool the air delivered, turn the
temperature knob to the desired setting.
In AUTO mode the system will cool and dehumidify the
air inside the vehicle. Also while in AUTO mode, the
system will maximize its performance by using
recirculation as necessary.
Heating
On cold days when using manual operation of the
automatic system, choose oor mode to deliver air to
the oor outlets. To warm or cool the air delivered, turn
the temperature knob to the desired setting.
If you want to use the automatic mode, press
AUTO and adjust the temperature by turning the
temperature knob.
The heater works best if you keep the windows closed
while using it.
Defogging and Defrosting
You can use either defog or front defrost to clear fog or
frost from your windshield. Use the defog mode to
clear the windows of fog or moisture. Use the front
defrost button to defrost the front windshield.
-(Defog):Use this setting to clear the windows of fog
or moisture. Press the mode button to select this
setting. This setting will deliver air to the oor and
windshield outlets.
0(Front Defrost):Press the front defrost button to
defrost the windshield. The system will automatically
control the fan speed if you select defrost from AUTO
mode. If the outside temperature is 40°F (4°C) or
warmer, your air conditioning compressor will
automatically run to help dehumidify the air and dry the
windshield.
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Operation Tips

Keep the hood and front air inlets free of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
Keep the air path under the front seats clear
of objects. This helps air to circulate throughout your
vehicle.
Adding outside equipment to the front of your
vehicle, such as hood-air deectors, etc., may affect
the performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
Rear Air Conditioning System
If your vehicle is equipped with the optional rear air
conditioner it has two rear air conditioning fan speed
selectors. One fan speed selector is located in the
overhead console and the other is located in the
headliner above the second row seats.
To increase and decrease the ow of cooled air to the
rear vents, turn the knob to the fan speed you want.Front Control
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The knob has three speed positions. To increase the
ow of cooled air, turn the knob clockwise. To decrease
the ow of cooled air, turn it counterclockwise. To
turn the fan off, turn the knob to the off position.
To operate the rear system using the front control, just
turn the knob to the fan position you want.
To use the rear control, rst turn the front control to the
AUX position. Then, the rear control can be used to
increase and decrease the airow.Rear Air Conditioning and Heating
System
If your vehicle is equipped with this system, there are
two rear heat and air conditioning controls. One control
is located in the overhead console and the other is
located in the headliner above the second row seats.
The system can be controlled from the front controls as
well as the rear controls.
The front control has three knobs that control airow
speed, temperature and airow location. Rear Control
Front Control
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Rear Air Conditioning and Heating
System and Electronic Climate
Controls
With this system the front or rear passengers can
control the air temperature, air ow and fan speed for
the rear seat passengers. The climate control has
an overhead control near the driver and a control on the
back of the center console.
Driver Overhead Control
To control the rear climate control from the front seat
position, use the driver overhead control. The rear
console control must be on.AUX:Turn the knob, located on the left side of the
control panel, to this position to allow the rear seat
passengers to have control over the rear climate control
system. See “Rear Passenger Console Control” later
for more information.
9(Off):Turn the knob, located on the left side of the
control panel, to this position to turn the rear climate
control system off.
9(Fan):To adjust the airow speed, turn the fan
knob located on the left side of the control panel to the
desired setting. Choose AUTO if you want the system
to automatically choose the fan speed to maintain
a selected temperature. See “Auto Mode” later in this
section for more information on using this feature.
°F (°C):To adjust the air temperature, turn the
temperature knob on the center of the control panel. For
cooler or warmer air turn the knob counterclockwise
toward 66°F (19°C) or clockwise toward 82°F (27°C).
To regulate the airow direction, adjust the right knob on
the control panel. Turn the knob clockwise for oor vent
airow or counterclockwise for headliner vent airow.
Generally, the upper vents are used for air conditioning
and the oor vents for heating. The knob can be set to
any blend setting. Choose AUTO if you want the system
to automatically regulate the airow. See “Auto Mode”
later in this section for more information on using this
feature. Front Controls
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Battery Warning Light
If this light is displayed
when the engine is
running, you may have a
problem with your charging
system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the light stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this light displayed could drain
your battery.
If you must drive a short distance with this light
displayed, it helps to turn off all your accessories, such
as the radio and the air conditioner.
Voltmeter Gage
When your engine is not
running, but the ignition is
in RUN, this gage
shows your battery’s state
of charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power
at engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
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