freightliner MT45 2019 - HVAC Control Panel; Control Panel Operation and Modes

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Genuine OEM Parts 1.800.233.4823 www.morganolsonparts.com
SERVICING AND
TROUBLESHOOTING
A/C-HEATER-DEFROSTER
CONTROL PANEL OPERATION
BLOWER CONTROL The blower control provides three choices of air velocity in every oper-
ating mode. When the blower switch knob is rotated fully counterclockwise (with the knob indica-
tor pointing straight up) the blower is turned OFF. Rotating the knob clockwise will progressively
increase the air velocity.
TEMPERATURE CONTROL
The temperature knob controls
the discharge air temperature
in all operating modes. Turning
the knob to the right (red zone)
increases temperature; turning
the knob to the left (blue zone)
decreases air temperature.
Temperature control is achieved
through the regulation of engine
coolant through the heater coil.
BLOWER TEMPERATURE MODE A/C CONTROL (Upper Switch)
CONTROL CONTROL SELECTION AIR SOURCE (Lower Switch)
MODE SELECTION SWITCH
Dash
When this mode is selected, all air is discharged through the dash louvers.
Bi-Level With this setting, air is discharged through the dash louvers and onto the
oorboard. This is the ideal mode for rapid warm-up in cold weather.
Floor
This mode will direct all air to the oorboard. This mode is most frequently
selected when driving in cold weather with a clear windshield.
Floor/Windshield When this mode is selected, air is discharged onto the oor-
board and onto the windshield.
Defrost/De-fog This mode will direct most of the air to the windshield and pro-
vides for rapid defrosting of the outside of the windshield and defogging of the
inside surface. A reduced volume is provided for oor heating.
A/C CONTROL
The blue rocker switch will engage the A/C compressor when the upper edge of the
switch is pressed. Pressing the lower side of the switch will turn the compressor off.
AIR SOURCE CONTROL
The green rocker switch permits the driver to re-circulate cabin air or introduce outside
air to the cabin. Pressing the upper edge of the green rocker will recirculate cabin air;
pressing the lower edge of the rocker will return the ow of outside air.