The temperature sensor monitors refrigerator interior temperature and relays data to the control board. Based on sensor readings, the board activates the compressor, evaporator fan and condenser fan to maintain proper cooling levels. A faulty sensor providing inaccurate data can cause excessive cooling system operation, over-chilling the fridge. Use a multimeter to test the sensor by heating and cooling it while checking resistance values. Resistance should increase with higher temperatures and decrease at lower temperatures. Lack of resistance change indicates a defective sensor giving false temperature readings. The control board depends on accurate data from the sensor to properly activate cooling components. A malfunctioning sensor results in unnecessary compressor and fan activity, over-cooling the interior.
The temperature control thermostat regulates voltage to the compressor, evaporator fan and condenser fan to maintain proper refrigeration. A malfunctioning thermostat can over-cool the refrigerator. To check the thermostat, turn it from the lowest to highest setting listening for a click, indicating it's switching internal contacts on/off. No click could mean a defective thermostat needing replacement. Use a multimeter to check thermostat electrical continuity at different temperature settings. A properly working thermostat will show continuity at some switch points. Lack of continuity at any setting confirms a defective thermostat requiring replacement.
The thermistor sensor monitors refrigerator air temperature and relays readings to the control board. The board then adjusts compressor and evaporator fan operation to maintain proper cooling levels. A faulty thermistor can falsely signal warm temperatures, causing over-cooling. To test the thermistor, use a multimeter to check resistance values at different temperatures. Resistance should increase as temperature rises, indicating an accurate, working thermistor. Lack of resistance change or continuity means it is providing inaccurate data. This causes unnecessary compressor and fan activity, over-chilling the fridge. The control board depends on precise thermistor readings to properly activate cooling components. Faulty thermistors give false temperature data, leading to excess cooling. Replacing a confirmed defective thermistor restores accurate temperature monitoring so the control board can regulate refrigeration and prevent over-cooling issues.
The temperature control board regulates voltage to the compressor and fans to maintain proper cooling levels. A malfunctioning board can cause continuous operation, over-chilling the refrigerator. However, control boards are often misdiagnosed as bad when another part is actually defective. Before replacement, first thoroughly test the compressor, fans, thermistor and thermostat since they more commonly fail. If those components check out good, the control board may be providing continuous voltage to the cooling system.
The main control board is rarely the direct cause of refrigerator problems. Do not replace the control board until testing all other potentially faulty parts first. Components like the thermostat, thermistor, compressor and fans fail more often than the board. Thoroughly inspect and test those parts for correct operation before assuming control board failure. Only after confirming no other defective components are present should the main board be considered the issue. Control boards themselves usually function properly when given accurate data. Replace the main board only after ruling out problems with the thermostat, thermistor, compressor, fans and other commonly defective refrigerator components.
The main control board is rarely the direct cause of refrigerator problems. Do not replace the control board until testing all other potentially faulty parts first. Components like the thermostat, thermistor, compressor and fans fail more often than the board. Thoroughly inspect and test those parts for correct operation before assuming control board failure. Only after confirming no other defective components are present should the main board be considered the issue. Control boards themselves usually function properly when given accurate data. Replace the main board only after ruling out problems with the thermostat, thermistor, compressor, fans and other commonly defective refrigerator components.
The refrigerator air damper regulates cold air flow into the fridge compartment. If the damper sticks open, excessive cold air enters and overcools the space. To check, manually operate the damper through its full range of motion. The damper should move freely and completely close off air flow. If it stays partially open or does not move smoothly, the damper is defective and requires replacement.
The air damper regulates cold airflow into the refrigerator compartment. If the damper control is broken or stuck open, excess cold air enters the fridge. Inspect the damper operation by manually moving it through its full range. The damper should close completely to restrict air. If it stays partially open or does not move freely, the control is defective. Replace a confirmed broken damper control to properly regulate cold air intake.
The evaporator fan motor circulates air over the evaporator coils to generate cold air that chills the refrigerator and freezer compartments. If the fan motor malfunctions, cold air can accumulate in ducts and freeze food. To check the fan, manually spin the blades to see if they turn freely. Seized blades indicate seized motor bearings needing motor replacement. Use a multimeter to test motor electrical continuity. No continuity means the motor won't run at all. A working motor allows blades to freely draw air over the evaporator coils to properly circulate cold air and prevent freezing. Restricted blades or lack of continuity confirm a bad fan motor. Replacing a confirmed faulty evaporator fan motor restores proper cold air circulation through the compartments.
To prevent freezing, allow space between refrigerated foods and the cold air vents. Air blowing directly on food from a close vent can over-chill and freeze items. Keep several inches minimum distance between vents and perishables. Also avoid packing shelves too densely in front of vents. Ample airflow space enables air to circulate rather than blast concentrated cold on foods.
To resolve an over-cooling refrigerator, first adjust the temperature control to a warmer setting. Look for the recommended temperature range, typically 34-38 degrees Fahrenheit, and set the control within that. Then allow 24 hours for the higher temperature setting to take effect throughout the refrigerator interior. This gives time for the cold air to cycle out and warmer air to stabilize at the new thermostat setting.