Hello all
I have a 1998 2.0t which has developed a crazy fault. It will run for weeks then suddenly when I go to start in the morning the battery is Completely Flat! Nothing has been left switched on, and once it is jumped by another car it runs beautifully until the next flat battery incident which can happen at any time apparently without reason.. This is a new battery and dealer says alternator is charging properly. Any ideas?
All help greatly appreciated.

It is hard to tell where but there is a relay sticking somewhere or a motor is sticking.I have seen the Vaccum pump that is located under the L/S front of the car get water in the relay and the pump stays running.That will kill the battery.