If it were mine, the first thing I'd do is stick a voltmeter on the
engine battery and (1) see what it reads after the engine has been off
overnight, then (2) start the engine and see what it reads. Tap the gas
pedal if needed to turn off the red alternator light on the instrument
panel.

This would tell me whether the battery is holding a charge and whether
the alternator is doing a good job charging. Should read well above 13V
when charging.

There is a considerable voltage loss between the battery and the
dashboard when the headlights are on, mainly because the wire between
the battery and the dash is mighty skinny; but I don't know whether
that's enough to make the battery indicator go into the yellow zone even
with the engine running or not.

So I'd start with seeing what's going on at the battery, first.

--
Jack "Rocket j Squirrel" Elliott
1984 Westfalia, auto trans,
Bend, Ore.

On 10/08/2014 08:55 PM, Jeff Palmer wrote:
> Funny question.  85 Westfalia, automatic, original starter and
> alternator.  My kid flicked the battery indicator switch on a few
> weeks ago and i've been watching it.  Generally it only hits green
> when the engine is running.  At rest it's yellow.  When the engine is
> running, and the headlights are turned on, I'm down to yellow.
> Normal?  Or problem with the indicator?  Or charging problem?
>
> Thanks Jeff
>