2007 RAM CHASSIS CAB Owners Manual

Air Conditioning and Heating — If Equipped
Air Conditioning Operation
To turn on the Air Conditioning, set the fan
control at any speed and press the snowflake
button located at the right of the control panel.
Conditioned air will be directed through the outlets selected by the mode control. A light in the
snowflake button shows that the air conditioning is on.
Press the button a second time to turn the air condition-
ing off.
Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
The mode control (at the right of the
control panel) can be set in any of the
following positions:Air Conditioning And Heating UNDERSTANDING YOUR INSTRUMENT PANEL 233
4

NOTE: To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.
Recirculation Modes (Panel or Bi-Level)
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel only or through
both the panel and floor vents depend-
ing on the selected mode (panel vs bi-level).
NOTE: Selecting a “Recirculation Mode” mode does not
necessarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel. Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
Floor
Outside air flows primarily through the floor out-
lets located under the instrument panel.
Mix
Outside air flows in equal proportions through the
floor and defroster outlets, and the air conditioning
may be on.
Defrost
Outside air is primarily directed to the windshield
through the defroster outlets located at the base of
the windshield, and the demister outlets located at the
edge of each side of the instrument panel, and the air
conditioning may be on.234 UNDERSTANDING YOUR INSTRUMENT PANEL

Blower Control
The rotary knob on the left of the
control panel is the blower control.
Turn the knob clockwise to one of the
four positions to obtain the blower
speed you desire. To turn the blower
off, turn the knob to the far left posi-
tion.
Temperature Control
The rotary knob at the center of the
control panel controls the temperature
of the interior air. You can choose your
degree of comfort by rotating the
knob. The coldest temperature setting
is to the extreme left (blue region) and
the warmest setting is to the extreme
right (red region) of the rotation. Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use. To
remove frost from the side windows, it is best to use the
full defrost mode.
NOTE: When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the air
conditioning system has been on. It is not an indication of
a problem with the air conditioning system. UNDERSTANDING YOUR INSTRUMENT PANEL 235
4

Air Conditioning with Dual Zone Temperature
Control — If Equipped
With the Dual Zone Temperature Control System, each
front seat occupant can independently control the tem-
perature of air coming from the outlets on their side of
the vehicle. Air Conditioning and Heating Operation
To turn on the Air Conditioning, set the fan control at any
speed and press the snowflake button located on the
control panel. Conditioned air will be directed through
the outlets selected by the mode control. A light in the
snowflake button shows that the air conditioning is on.
Press the button a second time to turn the air condition-
ing off.
A/C Pushbutton
With the fan control in the ON posi-
tion, pushing the A/C button turns on
the air conditioning compressor. An
indicator light on the button shows
that the Air Conditioning compressor
is on. Conditioned air is now directed
through the mode outlets selected.
Pushing the button a second time turns the compressor
OFF.Dual Zone Control Head236 UNDERSTANDING YOUR INSTRUMENT PANEL

Recirculation Pushbutton
Pushing the Recirculation button al-
lows interior air to recirculate continu-
ously in any position except defrost
and defrost/floor mode for rapid cool
down of the interior. See “Fast
Cooldown” later in this section.
Mode Control
The mode control allows you to
choose from several patterns of air
distribution.
NOTE: To improve your selection choices, the system
allows you to operate at intermediate positions between the major modes. These intermediate positions are iden-
tified by the small dots and give an even blend of both
modes.
Panel
Outside air flows through the outlets located in the
instrument panel. These outlets can be adjusted to
direct the airflow.
Bi-Level
Air flows through the outlets located in the instru-
ment panel and those located on the floor.
NOTE: There is a difference in temperature between the
upper and lower outlets for added comfort. The warmer
air goes to the floor outlets. This feature gives improved
comfort during sunny but cool conditions.
Heat
Outside air flows primarily through the floor out-
lets located under the instrument panel. UNDERSTANDING YOUR INSTRUMENT PANEL 237
4

Mix
Outside air flows in equal proportions through the
floor and defroster outlets.
Defrost
Outside air is primarily directed to the windshield
through the defroster outlets located at the base of
the windshield and side window demist outlets.
NOTE: The air conditioning compressor operates in
both Mix and Defrost or a blend of these modes, even if
the A/C button has not been pressed. This dehumidifies
the air to help dry the windshield. Blower Control
The rotary knob on the left of the
control panel is the blower control.
Turn the knob clockwise to one of the
four positions to obtain the blower
speed you desire. To turn the blower
off, turn the knob to the far left posi-
tion.238 UNDERSTANDING YOUR INSTRUMENT PANEL

Dual Zone Temperature Control
Use this control to regulate the temperature of the air
inside the passenger compartment. This is accomplished
by having separate temperature control slides for both the driver and front passenger. The blue area of the scale
indicates cooler temperatures while the red area indicates
warmer temperatures.
Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use.
NOTE: When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the airDual Zone Temperature Control UNDERSTANDING YOUR INSTRUMENT PANEL 239
4

conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
Operating Tips
Fast Cooldown
For a fast cooldown, turn the blower fan rotary knob to
the extreme right position, turn the mode control to the
panel fresh position, press the snowflake button to turn
on the air conditioning, and drive with the windows
open for the first few minutes. Once the hot air has been
expelled, close the windows and press the Recirculation
push-button. When a comfortable condition has been
reached, choose a mode position and adjust the tempera-
ture control slide and blower speed as necessary to
maintain comfort. For high humidity conditions it may
be necessary to remain in the Recirculation mode to
maintain comfort. Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it’s rainy or humid. In most cases
turning on the Air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield by using MIX Mode
position on the control. Adjust the temperature control
and blower speed to maintain comfort. Higher blower
speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.240 UNDERSTANDING YOUR INSTRUMENT PANEL