How can I troubleshoot a malfunctioning A/C in my Audi 80?

My Audi 80's A/C suddenly stopped blowing cold air. It was working fine yesterday but now it's just blowing warm air. What might be causing this and how can I fix it?

Start by checking the refrigerant levels in your A/C system. Low refrigerant levels can cause the A/C to blow warm air. If the levels are low, you may have a leak that needs to be fixed before recharging the system.

Another common issue with A/C systems is a faulty compressor. If your compressor is not functioning properly, it won't be able to cool the air. Have a mechanic check the compressor and replace it if necessary.