Putting in too much refrigerant can make the A/C cool worse, and not better. It can also damage expensive components. Here is what can happen: • A/C blows warm or not as cold: Too much refrigerant raises system pressure and prevents the refrigerant from circulating and changing states properly. • High system pressure: The high-side pressure can become excessive, especially on hot days or while idling. • Compressor damage: Excessive pressure makes the compressor work harder, potentially causing premature wear or compressor failure. • A/C shuts itself off: The pressure sensor/switch may disable the compressor to protect the system. • Cooling fans may run excessively: The vehicle may command the condenser fans to run at high-speed trying to reduce pressure. • Poor performance at idle: The A/C may seem cool while driving but become noticeably warmer when stopped. • Leaks or seal damage: Excessive pressure can contribute to refrigerant leaks at seals, hoses, or other weak points. • Potentia...