Your source of power for the headlights goes through
the ignition switch. The ignition switch may not be your
problem but it was mine. My headlights didn't work at all
with ignition switch and headlight switch on. It will do some
quirky things when the ignition switch starts to fail.

JB

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Michael Diehr
Sent: Monday, December 22, 2008 12:20 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Headlight swtich diagnostics?

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!