Tailgate draining battery? Help!

[Thesiggers]

Can anyone help us? We have a 2006 T5 California and are having battery issues. Having tried everything the only thing we have noticed is that the battery seems to drain when the tailgate is open and when it is open it makes an odd noise - sounds like it is repeatedly trying to close/lock despite the boot being up.
Does anyone have any idea how to stop this noise and whether our hunch that this might be draining the battery could be correct?

Thanks!
Andie

 

[Hotel California]

Is it the automatic last part pulling on tailgate?
Is it a fully automatic closing tailgate?

What does it do when close the tailgate?
What does it do when you push the lock/unlock botton on the key fob?

Have you looked at the lock itself?
Ubstruction , try to clean it .