Date:         Wed, 15 Feb 2006 14:14:39 -0500
Reply-To:     Tim Demarest <tim.demarest@POBOX.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tim Demarest <tim.demarest@POBOX.COM>
Subject:      Re: Instrument Cluster Woes
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 12:07 PM 2/15/2006 -0500, you wrote:
>Weird electrical problems aren't always attributable to grounds.

That's true, but having symptoms change when various loads are switched in
and out is a classic bad ground symptom... the primary ground is open, so
the instrument cluster is finding a path to ground through another circuit.
Changing that other circuit (turning on the headlights, in this case)
changes or removes that alternate ground path.

That's the first reason I'd check the grounds first.

The second reason is that corrosion on these 'ground crowns' is a classic
Vanagon problem, the older the van, the more likely this will cause problems.

The third reason is that cleaning the ground connections is a zero-cost
fix, if it works, then there's no need to go through the "buy and try"
method with new parts.

In fact, before any buying or trying,  I'd also reseat (pull out, plug back
in) the main instrument cluster connector (carefully, these are notoriously
fragile), and do the same with the headlight switch connector.

Re-seating all connections involved is electronic trouble-shooting tip #1,
sometimes that's all it takes to scrape away a bit of corrosion and bring
back good connectivity.


>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!