> People hook them up "wrong".
> The proper way is to use the alternator charging signal to connect the
> batteries only after the engine is started and running, not to use the
> ignition switch.

Indeed. From looking at a picture of the GoWesty kit picture I can't tell
much, but I'd guess that the starter is being allowed to draw current from
the second battery. The blue wire off the alternator is probably powering
the relay coil as it should, but the other side of the relay coil is
probably simply grounded. For the brief moment after the alternator starts
generating before the starter is disengaged, the starter is sucking juice
through that 30A fuse. It's an easy fix, though. Ground the relay coil
through the starter solenoid, which provides a viable ground path only when
the starter ISN'T turning. There's a second spade terminal on the starter
solenoid just for that, and some (many? most?) Vanagons even have a wire
that runs from that terminal up to the front somewhere.

--
John Bange
'90 Vanagon - "Geldsauger"