What is a common cause of high-side pressure in an A/C system?

An overcharge of refrigerant is a common cause of high-side pressure in an A/C system because when too much refrigerant is present, it overwhelms the system's ability to properly circulate and condense the refrigerant. This excess refrigerant expands during the compression phase and can lead to increased pressure readings on the high side. The system is designed to operate within specific pressure ranges, and when the refrigerant charge exceeds the manufacturer's specifications, this can result in elevated high-side pressure, which can stress components and lead to potential system failure.

Restricted airflow across the condenser, slipping fan belts, and broken compressor reed valves can also affect system performance, but they do so in different contexts, often leading to lower efficiency or other types of pressure issues rather than a straightforward increase in high-side pressure due to refrigerant overcharge.