I currently have an issue with my A/C on my 08 A6 C6.
It random works and randomly doesn't , meaning it doesn't blow air, cold or hot. After a couple minutes of driving it will random work.
This will only happen on rare occasions & start up.
No codes thrown.
any suggestions?

 

Does the blower motor run or is it intermittent? If it's intermittent, then I would suspect that the blower motor itself has stopped working, or for whatever reason isn't getting a steady 12v supply.