There is lots on this, google "parasitic battery drain vanagon"

The short answer, get a relatively accurate multi-meter, then measure
the amps between the battery and the van.  Next, remove fuses and
replace until there is no draw.

Most common culprit ever:  stereo.  Especially if wired to play
without key in ignition.

Tom

On Thu, Sep 27, 2012 at 11:54 AM, Jamie Fitterer
<fittdog8848@hotmail.com> wrote:
> HEy everyone,
>
> I thought I would post here to try and save some trouble.  I had an issue with Battery drain prior to putting in an AUX battery and now the AUX battery keeps getting drained as well.  My question is....Is there a common rogue power draw that we have seen many times over, or am I on the hunt for Red drawing power circuit?   I DO NOT want to take this to a mechanic as every time i do, I end up with more problems than when I went in.  Any suggestions would be very helpful.
>
> Thanks,
>