Why is my AC fan constantly running and how can I troubleshoot this issue?

Your AC fan may be constantly running due to a malfunction in the thermostat, a dirty air filter, or a problem with the fan itself. To troubleshoot this issue, you can start by checking and replacing the air filter, ensuring the thermostat is set correctly, and inspecting the fan for any visible damage or obstructions. If the issue persists, it is recommended to contact a professional HVAC technician for further diagnosis and repair.