Narrow it down
Air blows, but it is warm. Low refrigerant (usually from a leak), a compressor that is not engaging, or an electrical fault are the most common causes.
Cool at first, then gets warmer. Often a low refrigerant charge, an overheating condenser (blocked or with a weak fan), or a compressor clutch that cuts out.
Cold on the highway, warm in traffic. Points to condenser airflow — the cooling fan or a condenser clogged with dirt.
Weak airflow from the vents. Often a blocked cabin filter or a blower-motor problem rather than the cooling system.
Noise when the AC is switched on. Grinding or squealing can point to the compressor, its clutch or the drive belt.
Common causes
- Refrigerant leak from hoses, seals, the condenser or evaporator
- Compressor or compressor clutch failure
- Blocked or damaged condenser, reducing heat transfer
- Cooling fan problems — motor, relay or sensor
- Electrical faults — fuses, relays, pressure switches or control-panel issues
- Blend door or actuator faults, mixing hot air into the cabin
- Dirty cabin filter reducing airflow
What you can do
- Check that the AC button is on and the temperature is set to cold with recirculation selected.
- Listen for the compressor clicking on when the AC is switched on.
- Replace the cabin filter if it has not been changed for a long time.
- Avoid repeatedly topping up refrigerant without finding the leak.
When to get a professional inspection
If cooling has dropped noticeably, or you hear noises when the AC runs, have the system checked. We test performance and the compressor, check for leaks and inspect the condenser, fans and electrical controls, then explain the fix with an estimate before any work begins.
