1.Working Principle Adopts Negative Temperature Coefficient (NTC) thermistor core: Lower evaporator temperature → higher sensor resistance Higher evaporator temperature → lower sensor resistance The control unit converts resistance values into precise temperature readings to execute anti-icing and compressor control logic. 2. Standard Technical Specifications R25 nominal resistance: 5kΩ / 10kΩ (most common auto models) B-value: 3435K, 3950K Temperature tolerance: ±1℃ Operating temperature: -40℃ ~ 120℃ Fast thermal response copper tube probe, corrosion-resistant to condensed water 3. Product Structure Epoxy/glass sealed NTC thermistor core (anti-moisture, stable performance) Thin copper tube sensing head for tight contact with evaporator coils Stainless steel spring clip for fixed installation on copper pipes Automotive-grade high-temperature, waterproof wire Vehicle-specific waterproof plastic connector (IP65) 4. Core Functions Evaporator anti-freeze protection When the evaporator surface drops below freezing point, the module cuts off the AC compressor to stop ice buildup that blocks airflow and damages the refrigeration system. Compressor cycle control Adjust the clutch on/off frequency to maintain stable cold air output. Auxiliary refrigerant shortage diagnosis Persistent low evaporator temperature with weak cooling indicates insufficient refrigerant. Over-temperature safety protection Prevent overheating damage to the evaporator and compressor under abnormal working conditions. 5. Typical Fault Manifestations Evaporator freezes thick ice, weak cold air from vents AC compressor cycles on and off frequently Car ECU reports AC temperature error code Cooling effect fluctuates between cold and warm air 6. Application Range All passenger cars, SUVs, pickup trucks, vans, construction machinery vehicle air conditioning evaporator systems