Man o man!  I have this problem right now too.  Haven't had time to chase it
down, though.
So far:
*    Took apart the hi/low switch, no contacts were burned, all looked well.
*    Checked bulbs, OK
*    Checked the low reduction relay, looks great.  Besides, if that were
faulty then all lights would crap out I think.
*    On one side, when low beams are on, that side displays both high and low
beams on, and quite dim, too.  Indicates a x-over somewhere.

 Suspect that it's a bad connection, or?
AAAARRRRRGGGGGGHHHHHHH!
Randy

Yetterman wrote:

> With all of the helpful responses to the latest head light/ electrical
> problems, I have decided to enter mine.  I think it is unrelated to the
> previous versions of electrical mishaps.
>
> While driving the low beam lights have never had any problems, although
> once I hit the lever for the brights, ALL OF THE LIGHTS GO OUT!!  AND STAY
> OUT!!
>
> This can be pretty scary hauling down the highway, or in the last case
> when trying to pull off and let others pass in the Sierra's.
>
> After which I dismantled and through gods graces was able to re-build the
> turn signal/ Bright lever. TO no avail.  No blown fuses. No overheated
> headlight switch. Nada.
>
> Thankfully the lights usually reactivate themselves after a week or so,
> and then it is like it never happened, at least until I try and use the
> brights again.
>
> Now a days I have trained my hand to not reach for the Brights under any
> condition, while training my mind that this is just another little
> something special about my Vanagon.
>
> Any thoughts?
>
> And BARS leak is definetly a BAD IDEA.  I ended up buying my new radiator
> in Souix Falls, at a dealer. End of story.