[V8] flickering lights, voltage regulator?

Thu Nov 3 07:35:37 EST 2005

changes with engine speed....   hhhmmm..  voltage
regulator could do that, but perhaps the alternator
stator(I think thats what it's called) is not quite
round and is not hitting the brushes at a steady
pressure... maybe weak springs on the brushes ?

alternator is not too bad to take out...

I'd have it on the bench and check it out...

my .03 :)

Mike,
ex-V8(2)
ex-100(3)
ex-a4cabrio
current 93 100csqa owner ;)

--- Ed Kellock <ekellock at gmail.com> wrote:

> Been at the car with a meter.  Checked at both the
> jump-start posts
> under the hood and at the battery terminals.  Even
> though I have a
> digital meter, the fluctuation was observable.  The
> good news is the
> readings at both places were between 13.9 and 14.2
> volts.  I even
> checked the climate control readout and saw readings
> there consistent
> with the other two sites.
> 
> Car is fully warmed up with all consumers turned off
> and no clicking
> observed anywhere.
> 
> I did loosen and work the battery cable connections
> back and forth to
> possibly refresh the connection.  Also pulled the
> battery caps and all
> cells were up to an acceptable level.  There was a
> very small amount
> of moisture evident before removing the caps (two
> long ones that cover
> 3 cells each.)  Vent tube is present and clear.
> 
> Battery is an Interstate Megatron MT-93 850 cca.  It
> was in the car
> when I bought it in June of '99.  The car just sat
> for a month in the
> parking garage at work without being used.  I did go
> down and start it
> and drive around the lot a couple times maybe twice
> during the month.
> Never had any evidence of a weak battery.
> 
> It just so happens that I have another of the exact
> same battery in
> the garage.  I pulled it from a car at the junkyard
> about 4-6 weeks
> ago, dead as a doornail, but looking very new.  I
> brought it home and
> have trickle-charged it off and on since and it will
> now hold just
> over 12+ volts in between trickle-charges.  I could
> swap it if that
> seems a reasonable measure.
> 
> Still, seems to me there's a charging system
> fluctuation.  One
> previous suggestion was "could you have a bad
> connection to the field
> line to the alternator?"  I can go under the car
> later in the week to
> check this.  What exactly might I be looking for to
> do so?
> 
> The flickering is not present without the car
> running, is present
> without any electical consumers on, varies with
> engine speed, and is
> still present with electrical consumers on.
> 
> Ed
> 
> ----- Original Message ----- 
> From: "Ed Kellock" <ekellock at gmail.com>
> To: <v8 at audifans.com>
> Sent: Wednesday, November 02, 2005 7:33 PM
> Subject: Re: [V8] flickering lights, voltage
> regulator?
> 
> 
> > Just revisited this tonight when I brought the car
> home from
> sanctuary
> > in the parking garage at work after a month.  The
> flickering changes
> > with engine rpm.  The alternator was replaced with
> a Bosch reman
> > almost exactly 2 years ago.  I've noticed this
> flickering for a
> while
> > now.
> >
> > Going to go out with a meter and see what I can
> see.
> >
> > Ed
> >
> > ----- Original Message ----- 
> > From: "Buchholz, Steven"
> <Steven.Buchholz at kla-tencor.com>
> > To: "V8" <v8 at audifans.com>
> > Sent: Wednesday, October 19, 2005 3:43 PM
> > Subject: Re: [V8] flickering lights, voltage
> regulator?
> >
> >
> > > ... one key piece of information is whether or
> not the fluctuation
> > > frequency varies as a function of the engine
> speed.  If it does
> not
> > that
> > > does not completely exonerate the alternator,
> but it does tend to
> > cause
> > > one to consider other possibilities ...
> > >
> > > ... could you have a bad connection to the field
> line to the
> > alternator?
> > > ... is there possibly some load that is
> switching on and off in a
> > > rhythmic fashion ... say something like the A/C
> Compressor clutch
> or
> > > some other high load item ... seat heater
> perhaps?
> > >
> > > IME alternators are pretty robust and consistent
> in their
> operation.
> > > That said, I have replaced the alternator on one
> of my V8s ...
> > >
> > > Good luck!
> > > Steve B
> > > San Jose, CA (USA)
> > > >
> > > > I just went down to the parking garage. The
> condition exists
> > > regardless of
> > > > whether the headlights are on. I was
> struggling to think of a
> > better
> > > term
> > > > than flicker. It's more of a pulsation, barely
> noticeable, but
> not
> > > > imperceptible. If it's not dark you can still
> see it but
> sometimes
> > you
> > > have
> > > > to kind of blur your vision and look just to
> the side. This was
> > all
> > > based on
> > > > my observation of my center dome light.
> > > >  I think I'm going to go after the voltage
> regulator. In a
> rebuilt
> > > unit, it
> > > > may have been given only quick consideration
> and thought good.
> > I'll
> > > see what
> > > > tests I can run on it.
> > >
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> 
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