Hi all! This is my first question to this list, first car and I'm not a
mechanical person so you may have to bear with me here while I try to
make this make sense...
I have a slightly quirky 85 Wolfsburg ed. Westy Weekender. I've been
puzzling through the electrical system with a very electrically minded
friend, and we've come upon a deep cycle battery (quite dead) under the
drivers seat. The thing is that even with this battery dead, everything
in the van runs whenever we need it to. The deep cycle was only wired to
a lighter outlet under the front passenger seat. So what did the battery
power when it was live? There is a relay which would potentially connect
the deep cycle to the alternator/starting battery/main electrical system
but we cannot figure out what controls the relay. Anyone know? My buddys
best guess at this was that originally the deep cycle would power the
electrical system when the ignition key was off and then when the engine
was running the alternator would charge both batteries in parallel.
Thanks for any help you can give, and I hope this all makes sense...

-Arthur Anderson
Portland, ME.