What are the common causes of a blower motor failure?

Residential indoor air handler blower motors fail due to several common electrical, mechanical, and maintenance-related factors over their operational lifespan. One of the most frequent causes is a severely clogged, dirty air filter that starves the blower of airflow, forcing it to work against extreme static pressure, leading to chronic overheating and burnt-out motor windings. Another common culprit is a failed run capacitor, which robs the motor of starting torque and causes it to overheat. Electrical power surges, worn-out mechanical sleeve or ball bearings that bind the shaft, and insect or dust accumulation inside electronic modules also cause premature failure. You can monitor health by listening for unusual noises. You can verify failure when electrical testing confirms open windings or seized bearings requiring a full motor replacement.