How to diagnose a faulty air conditioning system in a Vauxhall Insignia?

The air conditioning in my Vauxhall Insignia is not blowing cold air. What could be the possible causes and how can I troubleshoot this issue?

Firstly, check the refrigerant level in your air conditioning system. Low refrigerant levels can cause the air to not cool properly. You can use a refrigerant gauge to check the levels.

Another possible cause could be a faulty compressor. Check if the compressor is working properly by turning on the air conditioning and listening for any unusual noises from the engine bay.

It is also worth checking the AC condenser and evaporator for any clogs or damage. These components play a crucial role in cooling the air and any issues with them can result in poor performance.