What are the most common issues with the HVAC system in an Audi 80?

I have noticed some issues with the HVAC system in my Audi 80 and I want to know what are the most common problems and how can I prevent them.

Another common issue is a leak in the AC system, which can cause a decrease in cold air output. To prevent this, have your AC system checked for leaks and have them repaired immediately.

A malfunctioning compressor can also cause problems with the HVAC system. This can be prevented by regularly checking the compressor belt and keeping it properly adjusted and replaced when needed.