The 83 diesel Vanagon in question has a 65 amp alternator. This model
uses a 3 pin connector that plugs into the alt so adding another wire to
the alt is not practical. It could be desirable to do so on the 90 amp
models as you say. Keep in mind that we are talking about resolving the
voltage drop that takes place from the battery through the dash wiring
and on to the headlights and grounds. In my experience the battery is
seeing a much higher voltage than the lights do after the dash wiring.
Bypassing the dash wiring with relays and a direct connection to the
battery resolves this drop.

Mark

Dennis Haynes wrote:
>
> The additional wire should really be run from the alternator. The
> alternator is the actual source of power when it is running and wires
> between it and the battery are not adequate for the 90 amp capacity.
>
> Dennis
>