Recirculation Mode; Temperature Control Switch - freightliner BUSINESS CLASS M2 Driver Manual

Heater, Ventilator and Air Conditioner
Mode: Directs 75 percent of the airflow to the
face outlets and 25 percent to the floor outlets.
3.
Air Conditioning Bi-Level Mode: Directs the
airflow equally to the face outlets and the floor
outlets.
4.
Selection between the Air Conditioning Bi-
Level Mode and the Face Mode: Directs 25
percent of the airflow to the face outlets and 75
percent to the floor outlets.
5. Face Mode: Directs all airflow through the face
outlets.
6. Selection between Face Mode and Floor
Mode: Directs the airflow equally through the
face outlets and the floor outlets.
7. Floor Mode: Directs all airflow through the floor
outlets.
8. Selection between Floor Mode and Floor/
Defrost Mode: Directs 75 percent of the airflow
through the floor outlets and 25 percent through
the defrost outlets.
9. Floor/Defrost Mode: Directs the airflow equally
to the floor outlets and the defrost outlets. The
recirculation button will not work in this mode.
10. Selection between Floor/Defrost Mode and
Defrost Mode: Directs 75 percent of the airflow
through the defrost outlets and 25 percent
through the floor outlets. The recirculation button
will not work in this mode.
11. Defrost Mode: Directs all airflow through the
defrost outlets. The recirculation button will not
work in this mode.

Temperature Control Switch

The temperature control switch is used to select the
desired temperature. Turn the switch to the left
(counterclockwise) for cool air, or to the right (clock-
wise) for hot air. There are 21 positions on the tem-
perature control switch ranging from full cool air to
full hot air.
Fresh Air Mode
Fresh air, or outside air, is circulated through the
heating and air conditioning system unless the recir-
culation mode, if equipped, is turned on.
6.3

Recirculation Mode

The recirculation mode is only available on vehicles
with air conditioning.
The recirculation mode limits the amount of outside
air entering the cab. Press the recirculation button to
prevent dusty or smoky air from entering the cab.
The recirculation mode can also be used to decrease
the time required to cool or heat the cab interior dur-
ing extreme outside temperature conditions. When
the recirculation mode is on, the recirculation indica-
tor will be on. See Fig.
The recirculation mode is not available when the air
selection switch is in one of the following modes:
•
floor/defrost mode
•
selection between floor/defrost mode and de-
frost mode
•
defrost mode
When the recirculation mode is turned on, it will stay
on for 20 minutes, or until the recirculation button is
pressed again, or the air selection switch is turned to
a defrost mode.
IMPORTANT: On vehicles built before May 2,
2003, the recirculation mode turns off after
twenty minutes and can be turned back on
when the recirculation button is pressed again.
On vehicles built from May 2, 2003, the system
enters a partial recirculation mode for five min-
utes after being in full recirculation mode for 20
minutes. This cycle repeats as long as the sys-
tem is in recirculation mode.
NOTE: To prevent the buildup of fumes or odors
inside the cab on a vehicle built before May 2,
2003, do not use the recirculation mode for
more than 20 minutes. It is recommended that
the recirculation mode remains off for five min-
utes before it is turned back on.
Defrosting
Before using any of the defrost modes, clear the
screen at the base of the windshield if snow or ice is
present.
6.2.