[s-cars] Another S6 Climate control question

[Mark Hahn]

  I hate to beat a dead horse but....  My S6 climate control started 
becoming intermittent a year or so ago. Seems worse in warm weather and 
almost totally reliable in the winter. I did purchase a good used head from 
a A4 but someone mentioned that they had a problem with theirs and found it 
was tied to the ignition switch? Any feedback from others who have had 
similar problems so we could get a majority consensus on where the fault 
'usually' lies??  Thanks to all once again.  MGH