Join Date: Jan 2008
Location: Boston, Lincs
Re: GTV Battery Discharge
Lots of Threads on here about this topic, do a search.
A lot of problems seem to be caused by an after market ICE, to check this remove the head unit and see if that cures it.
Other cases have been caused by poor connections on the battery.
If it isn't either of these the previous Threads will give you loads of advice on how to trace the problem, as long as your confident using a Digital Multi Meter.