If your car's air conditioner only works properly when the engine is running at higher RPMs or during acceleration, there could be a few potential reasons for this issue:
Faulty Compressor Clutch: The compressor is a crucial component of the air conditioning system, as it pressurizes and circulates the refrigerant to cool the air. The compressor clutch engages and disengages the compressor from the engine, allowing it to turn on and off as needed. If the compressor clutch is failing or not engaging properly, it may only work when the engine is running at higher RPMs, when there is more power available.
Low Refrigerant Levels: The air conditioner relies on a specific amount of refrigerant to function correctly. If the refrigerant levels are low due to a leak in the system, the AC may struggle to cool the air effectively at low RPMs but might work better when the engine is running faster.
Weak AC Components: Over time, various components of the AC system, such as the condenser or cooling fan, may become worn out or less efficient, leading to reduced cooling performance, especially at lower RPMs.
Engine Load: The air conditioning system puts an additional load on the engine. When the engine is running at higher RPMs or during acceleration, it can handle the increased load better, resulting in better AC performance.
Electrical Issues: There could be electrical issues, such as a faulty relay or wiring problem, that are affecting the proper functioning of the AC system.
Blocked Airflow: In some cases, the air intake for the AC system might be blocked or obstructed, reducing the system's efficiency at lower engine speeds.
To determine the exact cause of the issue, it is recommended to have the AC system inspected by a qualified mechanic. They can perform diagnostic tests, check the refrigerant levels, inspect the compressor clutch, and examine other components to identify the root cause of the problem and perform any necessary repairs. Timely maintenance and regular servicing of the air conditioning system can help prevent such issues and ensure proper cooling performance regardless of the engine RPMs.