Condenser fans suffer the same failures as evaporator fans. In addition to open windings, failed bearings, and misalignment, condenser fans my fail due to dirt. Because the condenser fan is beneath most refrigerators and behind a cover, it is easy to forget to clean it or the condenser coil.
Condenser Fan Motor
The photo above shows the condenser and fan of a fifteen-year-old Amana side-by-side that was probably never cleaned. It was replaced because it didn’t cool. A thorough cleaning of the condenser, fan motor, and fan blades restored it to proper operation. Don’t try to treat a new refrigerator this way; the fan motor and compressor might not survive the over-heating.
Although this fan still managed to rotate, sometimes the dirt and debris will jam the fan blades. Just make certain that you disconnect power before working on a condenser fan to prevent it from starting unexpectedly.