Ford Mustang defroster issue with no heat on passenger side on Ford Mustang

Some Ford Mustang owners report experiencing defroster issues characterized by a lack of heat on the passenger side. This problem may stem from a malfunctioning heater core, which is responsible for heating the air blown into the cabin. Additionally, issues with the blend door can lead to inconsistent heating, as it regulates the mix of cold and heated air. Some owners have noted that problems with control arms under the dash may affect the transition from AC to heat, disrupting hot air distribution. Furthermore, mode actuators that control airflow direction can develop issues, such as stripped gears, resulting in imbalanced heating. Lastly, disconnected or misplaced vacuum hoses can hinder the heating system's performance, causing cold air to blow from specific vents or getting stuck in defrost positions. It is advisable for owners experiencing these issues to check these components and seek professional assistance for effective diagnosis and repair.