Good afternoon,

A6 saloon V6 3.0L TDI 2012

My A6 will only blow warm on drivers side (passenger side works normal) from all vents. The dial is not digital and will turn down to cold but on maximum 24 it is actually only about 10 degrees. This started suddenly and my local reliable garage have tested the heating system and have said there is no faults showing and suggested something may be blocking a vent which would mean removing all the dash with considerable labour charge just to expose/diagnose.
I'd appreciate and advice/help please.

Thanks
Steve.