Not to be critical, but is there an image showing wires in a less, uh,
messy way?

The little silver box is a relay. Likely the isolator relay. And yes
it is most likely grounded throught the case.

Was the battery functioning before?

The best way to trace wiring is to disconnect ALL batteries, consult a
wiring diagram, and when you narrow it (mystery wire) down to a few
(or one) wire, disconnect it, ground it, and check for continuity with
a VOM.

What year is van?

On 6/29/07, Loren Busch <starwagen@gmail.com> wrote:
> Sorry for the repeat post but got no answers at all to the first post.
> In the process of going to a larger aux battery (under the rear seat) I'm
> also planning on going to a Surepower 1315 separator rather than the current
> relay setup.  Now that I'm looking at the rats nest of wiring that already
> exists in the aux battery box I'm confused.  Picture here:
> http://picasaweb.google.com/starwagen/AuxBatteryCompartment/photo#5081175084108326066
> The two red wires that disappear to the lower left connect to what I assume
> is a relay, mounted in the 'hidden' space with two bolts that go through the
> body into the wheel well, nuts in the wheel well.
> If the gurus can take a look at the picture and tell me a little bit about
> what I'm looking at I'd really appreciate it. Like what is the little square
> silver box at the top of the picture?  Seat belt buzzer? Or what?  And if
> the relay (that is hidden) is the 'Aux Battery Relay' I have to assume that
> it grounds through the case (only two wires to it).
> Any definitions would help so I can sort these wires out .
> Thanks in advance.
>

--
Neil Nicholson. 1981 Air Cooled Westfalia.

http://web.mac.com/tubaneil