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Defrost Termination Sensor Malfunction

Likely causes

NTC thermistor failure — resistance value drift

Check: Measure NTC thermistor resistance — normal 10kΩ at 25°C; verify resistance changes with temperature; fixed value = failure

What to do: Replace with same spec NTC thermistor; verify defrost termination temperature operation after replacement (+10~+13°C activation)

Thermostat contact failure — defrost not terminating

Check: Check thermostat set temperature — normal defrost termination +10~+13°C; if it doesn't open above this = contact welding or failure

What to do: Replace thermostat (same temperature rating); if contact welded, also inspect heater simultaneously

Sensor position displaced — detached from coil

Check: Check sensor clip mounting position — should be firmly clipped to coil surface; if detached or gapped = temperature sensing delay

What to do: Re-clip sensor to coil; reinforce contact with thermal grease if needed; verify defrost temperature operation after reinstallation

Field tip

Defrost termination sensor diagnosis order: ①check sensor position → ②measure resistance → ③test thermostat contact — NTC 25°C 10kΩ and thermostat +10~+13°C standards should be memorized

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