On Sep 27, 2006, at 12:20 PM, Kenneth Wilford wrote:

> Does the van have wiring for a towing wiring harness?  If so rip it
> out and
> your problems will vanish.
>
> Thanks,
> Ken Wilford

I recently went to install trailer wiring, and discovered that no
fewer than THREE other harnesses had been wired in, in different
locations.  It was a mess.    I ripped them all out and started fresh.

FYI, many US trailers are 4-wire (ground, running lights, left &
right).  The left & right side do dual duty as brake & turn signals,
as they do on most american cars.     The Vanagon of course uses
separate Turn & Brake lights.

So in most cases you need the trailer wiring harness that includes a
little electronic box which combines the turn & brake lights from the
vanagon to the 4 wire version.