Low refrigerant or system leaks
Refrigerant normally circulates in a sealed system. If the level is low, the workshop should check for leaks instead of repeatedly topping up the gas.
Compressor and control faults
The compressor, clutch, control valve, pressure sensor or electrical supply may prevent correct cooling even when refrigerant is present.
Blocked cabin filter or airflow issue
A clogged filter, blower problem or evaporator restriction can reduce air volume and make the AC feel weak.
What an AC diagnosis may involve
Pressure readings, temperature checks, leak testing, compressor command, condenser airflow and electrical inspection help identify the actual cause.