Genuine Daikin 1407130 Outdoor Air Thermistor Assembly is the sensor assembly that reads the outdoor air temperature, giving the system the outside reading it uses to run correctly. When it starts to fail, the outdoor unit may lose output, run hot or cold for conditions, or stop and start at odd times. A genuine assembly reads the air the way your Daikin expects, keeping the system accurate — where a non-genuine part can read off and leave it running incorrectly.