To add to Gareth's advice, on older audi models if the hazard switch fails or starts to fail it can cause the I dictators to play up. If that's the case the cure is a new hazard switch
Oh wow, great stuff Tony 😊 sorry I've not arranged shows this year. Since my Audi is off the road and my mate Jack emigrated with his TT I've lost the heart to organise the stands.
Not sure if these threads will help:
https://forums.tdiclub.com/index.php?threads/vacuum-routing-refresher.257619/
https://forums.tdiclub.com/index.php?threads/volkswagen-tdi-alh-vacuum-diagrams-stock-modified.290286/
https://www.audizine.com/forum/showthread.php/656655-Vacuum-Hose-Routing-Diagram
https://www.audiworld.com/forums/a8-s8-d3-platform-discussion-60/need-vacuum-hose-diagram-2784211/
No you should be able to I think. I think it'll depend if it has canbus which was first introduced either in 2003 or 2004. My A6 is pre canbus so it's slightly harder due to the system not being as complex as later ones. But either way a competent mechanic should be able to diagnose it.
Id recommend a diagnostic check to see if any fault codes flag up. Could be an issue with the window switch. Or bizarrely it might be worth checking the battery to make sure it's working efficiently as a failing battery can throw up unusual electrical gremlins
Just checked similar threads. I member had a similar issue with there A1 and the positive terminal had corrosion which was stopping it from starting properly: