01 - Condenser Coils are Dirty
The condenser coils are usually located under the refrigerator. They dissipate heat as refrigerant passes through them. If the condenser coils are dirty, they won’t dissipate the heat effectively. As debris builds up on the coils, the refrigerator becomes less efficient, causing the refrigerator to work harder to cool down. If the coils are significantly dirty, the refrigerator will not be able to maintain the proper temperature. Check the condenser coils to determine if they are dirty—if the condenser coils are dirty, clean them.
02 - Evaporator Fan Motor
The evaporator fan motor draws air over the evaporator (cooling) coils and circulates it throughout the refrigerator and freezer compartments. Some refrigerators have more than one evaporator fan motor. On refrigerators with only one evaporator, the evaporator is located in the freezer compartment. If the evaporator fan is not working, it will not circulate the cold air to the refrigerator compartment. If this occurs, the freezer may still get cold, while the refrigerator will not get cold. To determine if the evaporator fan motor is defective, try turning the fan blade by hand. If the fan blade does not turn freely, replace the fan motor. Additionally, if the motor is unusually noisy, replace it. Finally, if the motor does not run at all, use a multimeter to test the motor windings for continuity. If the windings do not have continuity, replace the evaporator fan motor.
03 - Thermistor
The thermistor monitors the refrigerator temperature and sends the temperature reading to the control board. The control board regulates power to the compressor and evaporator fan based on the thermistor readings. If the thermistor is defective, the compressor and evaporator fan may not run when necessary. As a result, the refrigerator will not be cold enough. To determine if the thermistor is defective, test it with a multimeter. The thermistor resistance should change in conjunction with the refrigerator temperature. If the thermistor resistance does not change, or the thermistor does not have continuity, replace the thermistor.