I have a 2006 Audi A6 Avant 2.7 TDI Quattro and from time to time the electrics start blinking intermittently. The headlights, tail lights, instrument panel, MMI, all start flickering, but to date I have not felt that the car engine or power is affected. It happens on rare occasions and to resolve the situation I pull over, turn off the ignition and remove the key and then re-start. it seems to do the to trick, but its not a good feeling.

If it was the alternator at fault, surely the problem would be a more consistent? Is there a fuse that governs the above? The condition seems to be sensitive to the instrument warning panel indicator, as I have noticed that if the windscreen top up fluid or brake pad warning signal (need replacing soon) appears, it provokes the condition above.
Any ideas?

 

I concluded that the main problem was the connection to the battery where the positive pole connection was loose.
I have now driven the car for nearly a month and all is well.

Having taken out the spare wheel housing in the boot well and releasing the battery, I was able to get at the battery and check / tighten all connections in the area.
There are quite a few connections, so it was well worth while checking and giving them all a slight tighten. The main culprit was the the main + connection which could be slightly moved by hand.

I didn't find any water problems, but it was well worth while inspecting the plenum chamber in the engine bay as it did need a clean.
Thanks for everybody's help and contributions.
For more detail see: Audi A6 2.7 TDI Intermittent Electrics