<SNIP>

2) I have a factory installed dual battery system that appears to be
isolated by a relay under the drivers seat.  How do I test that it is
functioning properly? ie. isolating the battery and discharging only
the cigarette lighter socket located under the passenger's seat that
the electric fridge plugs into?

I plan on adding a fuse block under the driver's seat for the
secondary battery and running my auxiliary equipment to it (Stereo,
Fridge, Lighting, etc...) but I'd like to know it's actually isolated
correctly first.

<SNIP>

To test the operation of the auxiliary battery relay, with the van off,
check the lighter socket on the right seat pedestal and make sure it has 12
volts present.
Next, disconnect the ground cable from the auxiliary battery, you should
not have any voltage at that socket.
Start the van, and 12 volts should be present at the socket again.
Just to make sure, you could turn off the van, reconnect the auxiliary
battery ground, disconnect the main battery ground and look for voltage on
the main fuse block and there shouldn't be any.

I recently installed a terminal strip under the drivers seat that I use to
connect various accessories to the auxiliary battery. Mine is divided into
three sections, constant 12 volts, amplifier control signal and ground. I
have photos of it in my Yahoo!Photo album, go to Vanagon, then to the In
Car Entertainment Album. Pictures DCP_0004 and DCP_0005 show the terminal
strip.

Tim Hannink
Winter Park, Florida
Goldibox - 1987 Vanagon Camper, Wolfsburg Edition
http://home.earthlink.net/~tjhannink/
http://photos.yahoo.com/tjhannink