Symptoms drivers describe
- Air cool but not cold, or warm at idle
- Weak airflow from the vents
- A musty smell when the system is switched on
- The compressor clutch not engaging
Possible causes
- Refrigerant loss through seals, hoses or the condenser
- A stone-damaged or corroded condenser
- Compressor wear or a clutch fault
- A blocked cabin filter restricting airflow
- Electrical or control faults, including pressure switches
What you can do
- Run the system regularly, including in winter, to keep seals in condition
- Note whether it is worse at idle or in traffic
- Mention the last time it was regassed
How we check it in the workshop
We check operating pressures and vent temperatures, inspect the condenser and compressor, and look for leaks rather than simply refilling a leaking system.
Is it safe to keep driving?
Comfort rather than safety, though air con also helps demist the windscreen quickly.