Mitsubishi Electric · R410A Systems
The indoor unit's fan motor is malfunctioning. This could be due to an electrical failure in the motor windings, seized bearings, or an issue with its control circuit, leading to insufficient airflow.
Click steps to track your progress.
Check the power supply voltage to the indoor fan motor terminals using a multimeter.
Measure the resistance of the indoor fan motor windings (if accessible) — compare to specifications.
Inspect the indoor fan motor for free rotation by hand (power off) and listen for unusual bearing noise.
Verify the fan motor speed feedback signal at the indoor unit PCB.