re: alternator idiot light

["R.P.M." <rm2a@domain.elided>]

Eric, I posted the same question when we got our 85 Graduate, and would
like to forward a little info that was imparted to me.  The first time I
noticed the glow was when we went out one night in December, lights turned
on and a Red glow of the idiot light when the blower was turned on or when
I shifted into reverse.   The Alternator Idiot Light that you have noticed
does glow faintly when there is a big draw on the electrical system.
Worst case scenario is a marginally operating alternator (perhaps from a
loose v-belt or worn brushes or something else internal), but more likely
is the fact that Alfas and older cars in general tend to get oxidation at
the connection points of the electrical systems, which leads to higher
impedences.  The idiot light circuit may be tapped into a circuit that has
a high impedence and senses it as low current being supplied.  Compounding
this situation by activating more accessories will make increase the glow.
Simple things being simple, try to improve the contacts of the electrical
connections by removing them one at a time, cleaning with fine sandpaper
or steel wool and dressing them with deoxit or dielectric grease. I found
that our battery did not have a bolt that holds the battery post (hard to
describe), so I put one in, brightened up the contacts and reinstalled it.
I also took out each fuse and cleaned the contacts. 
  
I don't know what actually remedied the red glowing idiot light in our
car, but figure it was worth the time as all is well.

I hope this helps!

roy
85 Graduate


> 
> Date: Tue, 4 May 1999 08:58:02 -0400
> From: eric.schnettler@domain.elided
> Subject: Alternator Question
> 
> My 88 Graduate has both a voltage meter and an alternator "idiot light" on
> the instrument panel.  When driving at night I've noticed a (very) faint
> red glow of the idiot light.  Additionally, the voltmeter indicates around
> 11 volts.  If I crank up the radio volume and hit the high beams I get a
> somewhat brighter red glow (but not the blazing "on" red like when you
> first crank the engine during an engine start) from the idiot light.  At
> high RPM I see a slight drop in voltage and at idle I have a higher
> voltage.  I'm assuming the drop in voltage at high RPM is caused by the
> ignition system placing more of a load on the alternator than at idle but
> this is just my guess.
>   It seems to me that the instruments are indicating a "real" alternator
> problem.  Can this be remedied by replacing the brushes in the alternator
> or does this warrant a new/rebuilt alternator?  I'd be interested in
> hearing anyone's opinion or experience with this.
> 
> Thanks
> Eric Schnettler
> 
> ------------------------------
> 
> Date: Tue, 4 May 1999 09:05:59 -0400
> From: Bill Bain <BBain@domain.elided>

- --
R. Moreno, M.D.
rm2a@domain.elided
Dept of Phys Med and Rehab
Univ of Virginia Health Sciences Center
(804) 924-0000

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