You should only need to have a 12v current that comes on at ignition to
energize the relay (So that the two batteries are "isolated" while the
bus is off, stopping one from discharging into the other). Basically
you just need the same deal as the stereo etc, key turns and the power
flows. I would imagine that you could just run a line from your fuse
panel to the relay. Use a test light to find a 12v line that comes live
when the bus is on would be my advice.

In my 73 Bus I ran it from my Coil which has worked for many a month
now.

Steve

> I have an '87 Vanagon 1/2 Camper (Weekender). My old alternator had a
> "W"
> connector with a light blue wire running from it up to the relay next
> to the
> aux. battery under the driver seat. I just replaced my alternator with
> one
> without the "W" connector. I was told this is no big deal as there is
> another way to energize the relay. Is anyone familiar with how I would
> go
> about doing that?
>
> Many thanks,
>
>         Matt Heydon
>