The answer to 'why is my central air short cycling' is that short cycling, where the air conditioner turns on and off rapidly, is often caused by an issue with the unit's compressor or a problem with airflow. This can be due to a variety of reasons, including a dirty air filter, a malfunctioning thermostat, a refrigerant leak, or a problem with the compressor itself.
Short cycling can put a strain on the air conditioner and lead to increased energy bills, uneven cooling, and potential damage to the system over time. It's important to address the underlying cause to restore efficient and reliable cooling.