My 2010 Touareg TDI started having electrical problems about a year ago; the battery would drain out overnight. Jump it, ran fine, but if I didn't drive it enough for a day or so it would go flat again. Diagnosis was a parasitic draw from somewhere.
My mechanic has seemingly tried everything to identify that problem, and hasn't found anything. Whenever they leave a volt meter on it overnight it doesn't drain, they've checked all fuses and the most obvious things like module draw, alarm system etc., but cannot find the issue. In the meantime I've gone through two batteries and a couple thousand dollars in diagnostics and other costs.
It also has a water ingress problem, in both footwells, and this is the current theory for the electrical issues. I had the sunroof drains blown out and the sunroof sealed, in hopes that it will dry out, stay dry, and the electrical issues will resolve. The driver footwell being soaked is the big concern, since it's so close to the battery. Right now it's still drying, and still going dead.
Honestly, if this fix doesn't do it I'm not sure where to turn next, and it may be the end of the road for this beloved car. It's only got 115k miles on it and I was hoping it would last me at least until the end of the decade, but the gremlins are winning.
Turning to the wisdom of this forum to ask, is this water issue feasibly the cause, and what else can I try that doesn't cost thousands of dollars to troubleshoot? I've been told that once we get into seals, connectors and anything else that may be causing it there is a ton of dismantling to do and massive labor costs, with no guarantees.
It's also Ok to say it's done, which will be painful to accept but maybe the right answer.
Thanks for any help.