One of the most common reasons for AC issues is a dirty air filter. The air filter captures dirt, dust, and other contaminants before they enter the air conditioner. When the filter becomes clogged, it can restrict airflow, which can cause your AC to not blow cold air. To fix this issue, you should change the air filter regularly, usually every 1-3 months, depending on usage and the environment. A dirty air filter can also cause the AC to work harder, leading to higher energy bills and reduced efficiency.