Refrigerators that have separate freezer and fresh-food sections and one evaporator located in the freezer section must have a working evaporator fan to maintain proper temperatures. This two sections and one evaporator arrangement applies to almost every refrigerator produced for the American market. Evaporator fans normally fail for one of three reasons.
1. Loss of power
2. Bad bearings
Loss Of Power
This can be caused by a variety of conditions, but the result is the same: no current flows through the evaporator motor. The fan doesn’t work and the temperatures in the freezer and fresh-food sections of the refrigerator rise. The refrigerator will likely not cool to the set point of the cold control and the refrigerator will run continuously except when it is in a defrost cycle. This problem can be caused by loose wires, an open fan motor winding, or malfunctions in electronic controls. Troubleshooting evaporator fans was once much easier than today. Most ran when the compressor ran and received 120 VAC from the defrost timer when it was in the compressor run position. With the introduction of adaptive defrost and electronic controls monitoring inputs from thermistors, fans don’t always run just because the compressor has started.
Defective evaporator fan bearings can keep the fan from rotating even though the windings are good. One should ALWAYS disconnect the refrigerator from the power source before checking the fan to see if it is binding. The fan blades should turn freely if the bearings are good. If the blades are difficult or impossible to turn the bearings are defective. Many times when evaporator fan bearing begin to fail a high-pitched squealing noise is emitted (leaving no doubt that the bearings are failing).
Misaligned fans can’t rotate freely because the fan blades strike the evaporator cover. Sometimes the fan is jammed and can’t turn at all; sometimes it turns, producing a knocking or clicking noise. This problem is the result of the general quality decline in refrigerator manufacturing and seems to plague the cheaper models (read Haier), although I have seen this defect on units costing over a thousand dollars. The solution is turn off the power, remove the evaporator cover, and loosen the fasteners on the evaporator fan mounting bracket so YOU can align and tighten it properly. The other choice is to try to get the manufacturer to honor its warranty and that may be far more difficult than adjusting a fan bracket.