Date:         Mon, 22 Apr 2013 00:15:36 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Speaking of cooling issues ...
Comments: To: Jeff Palmer <jpalmer@MYMTS.NET>
In-Reply-To:  <BLU0-SMTP127592AF293214E741578B6B8CB0@phx.gbl>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 09:53 PM 4/21/2013, Jeff Palmer wrote:
>I should also mention that the van used to run with the needle right
>on the blinking light, but now it's a bit low.  Also the fuel gauge
>never quite hits "F" anymore either.  I think that sounds like a
>voltage regulator issue if I recall?  I did order that part but
>haven't replaced it yet.  Did I mention two kids 2 and 4?

Just ground the kids...no, wait.  Your symptom is strong indication
of low voltage across the gauges.  Could be a bad regulator, but
could also be poor panel supply or panel ground.  Suggest measuring
in this order, ignition on:

1) Gauge voltage at temp guage, between ground pin (the skinny one)
and whichever gives the higher voltage.  Should be 10.0 +/- 0.5
V.  Briefly short the third pin to chassis ground while measuring,
voltage should change little and stay within spec.  If out of spec, then:

2) Panel ground at temp gauge ground pin voltage to chassis
ground.  Should be close to zero.

3) Voltages to chassis ground at regulator pins.  One pin should be
ground, one should be +10 V, one should be either close to battery
voltage or around maybe 0.7-0.8 V below it if a diode has been added
per TSB number I forget.  If supply and ground are good but output is
bad then it's the regulator, but it needs at least 11.5 V difference
between its supply and ground pins in order to regulate
properly.  Don't short the pins with your voltmeter probe.

Yrs,
d