Lincoln MKS air conditioning tapping sound upon activation that stops on its own on Lincoln MKS

Some Lincoln MKS owners report experiencing a tapping sound under the dashboard when activating the air conditioning, which may stop on its own. This noise is often attributed to a defective AC/heater system actuator that regulates airflow, or a bad blend door actuator that produces a knocking sound. Additionally, a malfunctioning blend door or mode door actuator may contribute to the issue by controlling the mixing of hot and cold air. Insufficient refrigerant in the AC system is another common cause of inadequate cooling, potentially due to leaks or lack of recharging. If the tapping ceases temporarily, it might indicate the system adjusting itself. To resolve these issues, owners are advised to replace any defective actuators, inspect blend door components, and ensure adequate refrigerant levels. If problems persist, consulting a professional mechanic or authorized service center is recommended for a comprehensive diagnosis.