KIT-SOCKET 3442750 - Caterpillar

Air Temperature Sensor (Recirculated Air)
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(4) Air Temperature Sensor (Recirculated Air)The air temperature sensor (recirculated air) is installed in an air inlet in the air conditioning unit. The air temperature sensor converts the air temperature in the cab into a resistance. This resistance is converted into a voltage signal that is sent to the control module.Air Temperature Sensor (Ambient Air)
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(5) Air Temperature Sensor (Ambient Air)The air temperature sensor (ambient air) is installed under the cab floor. The air temperature sensor converts the ambient air temperature into a resistance. This resistance is converted into a voltage signal that is sent to the control module.Water Temperature Sensor
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(6) Water Temperature SensorThe water temperature sensor detects the temperature of the engine coolant that flows into the heater core. The sensor then sends the signal back to the control module. This sensor is located on the inlet line of the heater core.Evaporator (Frost) Sensor
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The evaporator sensor is a semiconductor. When temperature increases, resistance decreases. On the other hand, when temperature decreases, resistance increases.The evaporator sensor is located at the discharge side of the evaporator coil. The evaporator sensor detects the temperature of the cooled air as the air is discharged from the evaporator coil. The sensor then sends the signal back to the control module.The control module switches the air conditioner clutch OFF when the temperature is under 3°C (37°F). When the air temperature becomes 4°C (39°F) or more, the air conditioner clutch is turned ON. This control module will also turn the compressor OFF in order to prevent the evaporator from freezing.Relay Switches
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(2) Compressor Relay (8) Relay (Condenser Fan) (13) Blower motor relayCompressor Relay
A relay switch is used to control the clutch on the refrigerant compressor.Relay (Condenser Fan)
A relay switch is used to control the fan for the refrigerant condenser.Relay (Blower Motor)
The relay controls the power to the speed control for the blower motor. When the relay is turned ON with a signal from the control module, the power voltage is supplied to the blower motor through the speed control.