MOTOR GP-PISTON 1377741 - Caterpillar

Operation Modes for Air Flow
Illustration 1 g00892720
(1) Actuator (Air distribution) (2) Actuator (Door Assembly) (3) Actuator (Air intake) (4) HVAC controller
Table 2
OPERATION OF ACTUATOR MOTOR (1)
(1)    
SELECTED MODE for AIR FLOW    Air Door (2)    ROTATION    
Degrees from Center
Panel     Air door (Floor vent)     9°    
Panel and Floor     60°
Floor     93°
Mixed     65°
Defrost     9°
Panel     Air door (Rear vent)     109°    
Panel and Floor     114°
Floor     155°
Mixed     180°
Defrost     139°
Panel     Air door (Defroster vent and Front Vent)     -13°    
Panel and Floor     -13°
Floor     21°
Mixed     55°
Defrost     55°
OPERATION OF ACTUATOR MOTOR (2)
(1)    
SELECTED MODE for AIR FLOW     Air Door (2)     ROTATION    
Degrees from Center
Maximum cooling     Air door (Door Assembly)     0°
Air flow through the heater core is blocked.    
Max heat     117°
Air flow through the heater core is not blocked.
OPERATION OF ACTUATOR MOTOR (3)
(1)    
SELECTED MODE for AIR FLOW     Air Door (2)     ROTATION    
Degrees from Center
Fresh air     Air door (Fresh air and Recirculating air)     90°
Fully opened    
Recirculating air     0°
Fully closed
( 1 ) Refer to illustration 1 in order to properly identify actuator motors.
( 2 ) Refer to the System Operations, "Air Conditioning System" section in order to properly identify the air doors.Note: Actuator motor (2) is part of the air door (Door Assembly). This motor is actuated when the operator changes the setpoint by pushing INCREASE or DECREASE on the temperature selection switch. Refer to "Initialization" for further information.Note: Actuator motors (1), (2) and (3) function similarly. Refer to Systems Operation, "Actuator Motor (Damper Assembly)" for schematic information.Operation of the Automatic Temperature Control mode (ATC)
Automatic temperature control switch If the heater/air conditioner is in the ON position, the code for automatic temperature control "AUT" causes the control module to enter the automatic mode of operation. In order to maintain the temperature of the cab at the setpoint, the control module performs the following steps:
Obtain the temperature setpoint of the cab that is located in non-volatile memory.
Adjust the speed of the blower fan.
Control the position of the air door (Door Assembly).
The control module controls the selection of the air outlets.
The control module controls the solenoid for the air conditioner.Operation of the Maximum Cooling Mode
Rotate the temperature control counterclockwise for Maximum cooling mode. The set point of the control is set at 15.5 °C (59.9 °F).When the system is in the maximum cooling mode, the control module will monitor signals for the following sensors:
Cycle the compressor clutch.
Operate the blower fan at the highest speed.
Temperature sensor (Outlet air)
Temperature sensor (Evaporator)
Sunlight sensorThe functions that follow are controlled automatically:
Blower fan speed
Air distribution
Temperature of the