Weird electrical problems aren't always attributable to grounds.

Recently, my turn signal light would flicker even when the turn signal
switch wasn't activated.  Then it went on "Steady" and the turn signal
lights wouldn't flash.  Also, the hazard switch didn't cause the lights
to flash.  The relay was good.  I unplugged and reseated the spade
connectors on the relay socket and all returned to normal.

Any and all connectors can be suspect when it comes to instrument
cluster weirdness.  So, if your light switch turns out to be good then
it's time to check grounds, the connections at the light switch, and others.

The voltage regulator in the cluster only regulates what goes to the
temperature and fuel gauges.

Mike

Michael Diehr wrote:
> My instrument cluster (85 vanagon with auto tranny, with tach)
> recently began exhibiting the following symptoms:
>
> Engine running.
> Headlight switch off:     All is well.
>
> Headlight switch on (either Parking lights or Headlights):
>   Parking and/or Headlights turn on as usual.
>   Water temp gauge drops to zero.
>   Tach drops to zero.
>   Clock turns off.
>   High beam LED glows dimly. (if i turn on high beams, the LED goes
> OUT, ironically)
>   Cluster illumination lights off.
>
> If i rotate the cluster illumination dimmer control, the tach & water
> gauge will flicker to life briefly.
>
> Headlight switch back to OFF:
>   Everything goes back to normal.
>   The water temp gauge blinks for a few seconds (as if you'd just
> turned on the ignition).
>
> Is this more likely a headlight switch failure?   Or perhaps ground
> problems in the fuse box?  Or the voltage regulator issue?
>
> thx!
>