Ok, more info:

I'm 99% sure it's not the headlight switch, as I've isolated the
problem : when I short across connector 30 to 58b (instrument panel
lite dim), instead of getting instrument panel lights, some of the
LEDs light up.  If I do this while the engine is running, then the
tach and clock go dead.

According to Bentley page 97.63, this current track goes as follows:

terminal 30 on headlight switch to terminal 58b on headlight switch
via the dimmer
Fuse S13
Track 68 (cigarette lighter light)
Track 67 (blower fan control lever light)
(to a mysterious circle labeled 22)
to the instrument panel lights via T14 connector 1
out to instrument panel ground via T14 connector 3
To ground, labeled 16

If I had to guess, I'd guess that Ground #16 is bad.  However, there
is no ground #16 listed in benteley on page 97.60.

I checked and cleaned the other grounds (including ground #10 the star
connector above the fuse box -- however my van only has one star
connector there).

Any idea where ground "16" lives?

On Dec 22, 2008, at 11:14 AM, Ken Wilford wrote:

> It does sound like a ground issue to me as well.  Check the grounds
> that
> are located behind the fuse panel.  You should be able to remove a
> couple of screws and drop the panel down and you will see the ground
> connections to the left.  There are a bunch and they are clustered
> together on a grounding "star" connector.  Check each ground on these
> two connectors and clean them as you go.  You will probably find that
> one of the ends of the ground wires has broken and you will need to
> crimp a new one on.  That is what I believe is going on.  The ground
> has
> gone bad and the headlights are seeking a ground through the
> instrument
> cluster.  You shouldn't need a new headlight switch but if you find
> you
> need something please let me know.
>
> Ken Wilford
> John 3:16
> www.vanagain.com
>
>
> Michael Diehr wrote:
>> 1985 Westy -- just last night started misbehaving.   Symptoms:  with
>> ignition off + headlight switch on, three LEDs in the dashboard glow.
>> With engine running + headlight switch off - normal.   Engine running
>> + headlight switch on, all dash instruments (including lighting) go
>> dead.   The load reduction relay seems to work fine (e.g. headlights
>> on + ignition on = headlights work, and when you crank the starter
>> the
>> headlights go out).  Toggling high beams doesn't do anything weird.
>> This sounds like a ground issue from a failing headlight switch?
>> Wiggling the ignition key doesn't seem to change anything in any
>> state.
>>
>> Unfortunately the van is about to go on a long trip, so need the part
>> asap etc.  Are there any surefire diagnostics I can do?  I have
>> voltmeter & bentley.  Thanks!
>>