From: John Lawton <piclist@jle.co.uk>
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Date: Tue, 8 Sep 2020 09:33:31 -0700
Subject: Re: [OT]:: Likelihood of car alternator fault being due to worn
 field	winding brushes?
Thread-Topic: [OT]:: Likelihood of car alternator fault being due to worn
 field	winding brushes?
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Sounds like a clear case for fitting a reconditioned unit.

John

On 08/09/2020 16:48, Bob Blick wrote:
> Hi Russell,
> If the brushes have gone bad, it's quite likely that other damage has or =
will soon happen to the alternator. Since it's a closed loop system, the re=
gulator is going to try to maintain current, so there might be arcing and e=
xcess heat which can damage the slip rings and potentially the regulator it=
self. Not saying that's what's happening here, but just fyi. The damage to =
the slip rings isn't going to be as bad as what happens in a motor with a s=
lotted commutator, you can probably clean it up good enough to get a few mo=
re years before the new brush is gobbled up.
> Cheers, Bob
>
> ________________________________________
> From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of Russ=
ellMc
> Sent: Tuesday, September 8, 2020 7:03 AM
> To: Microcontroller discussion list - Public.
> Subject: [OT]:: Likelihood of car alternator fault being due to worn fiel=
d      winding brushes?
>
> *TL;DR: If a 2001 Toyota Corolla alternator is faulty, how likely it is
> that the field winding brushes have gone open circuit?*
> It's reasonably likely that the alternator is the original one.
> ___________________
>
> My son's 2001 Toyota Corolla has stopped charging its battery.
> The battery holds charge and the alternator does not draw substantial
> current when off.
>
> Indications are that the alternator system is dead.
> It seems likely that there has not been a diode short circuit as in my
> experience these draw substantial battery current.
>
> A mechanic will remove and replace the alternator at an acceptable price.
> Alternator replacement is acceptable if necessary.
>
> *Can anyone suggest how likely it is that the field winding brushes have
> gone open circuit?*
> For various reasons I'm not inclined to do alternator diode replacements =
or
> other repairs but if brush failure was the cause then a repair sounds
> liable to be a sensible solution.
>
>
>
>          Russell McMahon
> --
>
>

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