My Refrigerator Evaporator Fan Motor Is Good When Tested But Won't Cycle On

Unplugged

• The evaporator fan motor only starts when the temperature control unit tells the motor that cold is building up around the inner coils. Because of this, a new refrigerator, or one that is recently defrosted by unplugging the machine, may not hear the sound of an evaporator fan for several hours. This lack of operation is a normal energy-saving behavior of refrigerators, since the inner coils are not at a freezing temperature. If re-installing an evaporator fan motor after testing, allow several hours to pass before verifying its operation.

Defrost Timer

• Many models of refrigerator feature an automatic defrost timer that occasionally defrosts the coils of the refrigerator without significantly interrupting vital machine operations. The defrost timer is one of two devices that operates the refrigerator evaporator fan. If the fan is not activating at proper times, the fault may lie with a malfunction in the defrost timer. Unfortunately, this part is not repairable and requires replacement. Contact a service professional for replacement options.

Temperature Control

• Part of the central control unit of the refrigerator, the temperature control unit regulates the temperature of the freezer, opening and closing vents as needed for keeping the desired constant temperature. If the temperature control is set to a temperature above freezing, the evaporator fan is not required since the coils are not in danger of icing over. In this instance, lowering the temperature in your freezer will activate the evaporator fan motor.

Compressor

• The refrigerator depends on refrigerant, in the form of a liquid, for heat absorption. This occurs when the refrigerant is channeled through the inner coils in liquid form. The refrigerant immediately expands into a gas and, in doing so, draws heat from the refrigeration and freezer chambers. The gas is then channeled to the outer coils where it expels its heat and then into a compressor where it is reliquefied. A faulty compressor does not properly reliquefy the refrigerant and, as a result, less heat is absorbed. This means the coils are not cold enough to freeze during operation and the evaporator fan is not required. Repairing or replacing the compressor will solve this problem.