After replacing a defective blower motor, if the motor spins but no air is coming out, what is a likely cause?

A situation where a newly replaced blower motor spins but does not push air can be attributed to several factors involving air flow restrictions or mechanical failures. In this scenario, reversed polarity to the motor is a strong candidate, as it can impact the direction in which the motor operates. If the motor rotates in the opposite direction due to reversed polarity, it may not be effective in drawing air through the system or may not be aligned with the fan's design to push air forward, leading to no airflow.

When a motor is designed, it typically has a specific direction of rotation necessary for optimal performance, especially in blower applications where air flow direction is critical. If the wiring is not connected correctly, this fundamental requirement is compromised, causing the observed issue of spinning without contributing to the airflow.

Other factors like a clogged air filter, a faulty switch, or a broken fan blade can also prevent airflow, but they involve different scenarios. A clogged air filter would restrict the air path, a faulty switch might prevent power or signal from reaching the motor, and a broken fan blade would mean the motor cannot effectively move air even if it’s spinning. Nonetheless, in this instance with the context of the motor operating but no air being moved, reversed polarity directly affects the motor's fundamental