A/C Intermittent Operation Due to Incorrect Refrigerant Charge

To diagnose an improper refrigerant charge, connect a manifold gauge set to the high and low side service ports while the engine is at idle. If the high-side pressure is excessively high, it may indicate an overcharged system or restricted airflow. If the pressure readings cycle rapidly between extremes, it confirms the pressure switch is triggering a safety shutdown. Ensure the refrigerant level matches the exact gram specification listed on the vehicle's under-hood factory sticker.