[DeTomaso] Techno question: a fine mess

Wed Oct 7 22:13:25 EDT 2015

My knowledge of electronics is microscopic, but my understanding is that a diode changes AC current (which is what an alternator makes) to DC

If the diodes in the alt are going out maybe they could cause the dancing voltmeter you describe.

Jim Oddie

-----Original Message-----
From: Joseph F. Byrd, Jr. <byrdjf at embarqmail.com>
To: 'Charles Engles' <cengles at cox.net>; MikeLDrew <MikeLDrew at aol.com>
Cc: detomaso <detomaso at poca.com>
Sent: Wed, Oct 7, 2015 3:54 pm
Subject: Re: [DeTomaso] Techno question: a fine mess

Do you have a voltmeter to see if the battery voltage is also going up
and
down?

I would first think a loss connection.  The alternator ground is
usually
through the bracket, so oxide surface faces could give high
resistance.
Joe/NC

-----Original Message-----
From: DeTomaso
[mailto:detomaso-bounces at poca.com] On Behalf Of Charles
Engles
Sent:
Wednesday, October 07, 2015 18:41 PM
To: MikeLDrew at aol.com
Cc:
detomaso at poca.com
Subject: Re: [DeTomaso] Techno question: a fine mess

Dear
Forum,

                     Thanks for all the tips and options.  
I will digest
them and attack the problem on Friday evening.

Is there a plausible explanation for the ammeter's bad
behavior with the
replacement stock alternator??       ....or is it just
some peculiarity of the
replacement alternator??

                                Warmest
regards,  Chuck Engles  (less
flummoxed)

From:
MikeLDrew at aol.com [mailto:MikeLDrew at aol.com]
Sent: Wednesday, October 07, 2015
1:06 PM
To: cengles at cox.net
Cc: detomaso at poca.com
Subject: Re: [DeTomaso]
Techno question: a fine mess

In a message dated 10/7/15 6 01 58,
hoppe1 at cox.net writes:

>                 I installed the back up
stock alternator.   I tested the
>    engine at idle and I am crushed that the
noise is still there.
>    So....the noise is from one of the belts or from the
idler pulley.

>>>Right.  You'd be amazed at how noisy a perfectly
good-looking belt 
>>>can
be.

Belts are cheap and consumable; those living
in an enclosed engine bay like
the Pantera's don't benefit from airflow as they
do in a front-engined car,
so probably have a shorter effective lifespan.  You
rarely get access to the
front of the engine, so now is probably a good time to
change them anyway.

The idler pulley bearing can make one hell of a racket. 
You can buy a
replacement bearing, then press (or have a machine shop press)
the old
bearing out and the new bearing in.  But the bearing is expensive, and
labor
adds further to the cost.  

Your local NAPA auto parts store has a
replacement pulley with bearing,
ready to bolt on, that costs less than the
cost of just a replacement
bearing for your old pulley.  It is slightly larger
in outside diameter, but
otherwise functions identically and allows the use of
the same-size belt.  

Part number is Duralast 231036.  Cost is about $13-15
if memory serves,
while just a replacement bearing for your old pulley is more
like $25, and
you haven't started paying machine shop costs.  

Changing the
belts first will determine if you need the pulley.  If you
don't, just return
it.  And if you do, have it in your hands and install
that next.

There, you
fixed it.
:>)

Mike

_______________________________________________

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-------------- next part --------------
   My knowledge of electronics is microscopic, but my understanding is
   that a diode changes AC current (which is what an alternator makes) to
   DC

   If the diodes in the alt are going out maybe they could cause the
   dancing voltmeter you describe.

   Jim Oddie

   -----Original Message-----
   From: Joseph F. Byrd, Jr. <byrdjf at embarqmail.com>
   To: 'Charles Engles' <cengles at cox.net>; MikeLDrew <MikeLDrew at aol.com>
   Cc: detomaso <detomaso at poca.com>
   Sent: Wed, Oct 7, 2015 3:54 pm
   Subject: Re: [DeTomaso] Techno question: a fine mess
Do you have a voltmeter to see if the battery voltage is also going up
and
down?

I would first think a loss connection.  The alternator ground is
usually
through the bracket, so oxide surface faces could give high
resistance.
Joe/NC

-----Original Message-----
From: DeTomaso
[[1]mailto:detomaso-bounces at poca.com] On Behalf Of Charles
Engles
Sent:
Wednesday, October 07, 2015 18:41 PM
To: [2]MikeLDrew at aol.com
Cc:
[3]detomaso at poca.com
Subject: Re: [DeTomaso] Techno question: a fine mess

Dear
Forum,

                     Thanks for all the tips and options.
I will digest
them and attack the problem on Friday evening.

Is there a plausible explanation for the ammeter's bad
behavior with the
replacement stock alternator??       ....or is it just
some peculiarity of the
replacement alternator??

                                Warmest
regards,  Chuck Engles  (less
flummoxed)

From:
[4]MikeLDrew at aol.com [[5]mailto:MikeLDrew at aol.com]
Sent: Wednesday, October 07, 2015
1:06 PM
To: [6]cengles at cox.net
Cc: [7]detomaso at poca.com
Subject: Re: [DeTomaso]
Techno question: a fine mess

In a message dated 10/7/15 6 01 58,
[8]hoppe1 at cox.net writes:

>                 I installed the back up
stock alternator.   I tested the
>    engine at idle and I am crushed that the
noise is still there.
>    So....the noise is from one of the belts or from the
idler pulley.

>>>Right.  You'd be amazed at how noisy a perfectly
good-looking belt
>>>can
be.

Belts are cheap and consumable; those living
in an enclosed engine bay like
the Pantera's don't benefit from airflow as they
do in a front-engined car,
so probably have a shorter effective lifespan.  You
rarely get access to the
front of the engine, so now is probably a good time to
change them anyway.

The idler pulley bearing can make one hell of a racket.
You can buy a
replacement bearing, then press (or have a machine shop press)
the old
bearing out and the new bearing in.  But the bearing is expensive, and
labor
adds further to the cost.

Your local NAPA auto parts store has a
replacement pulley with bearing,
ready to bolt on, that costs less than the
cost of just a replacement
bearing for your old pulley.  It is slightly larger
in outside diameter, but
otherwise functions identically and allows the use of
the same-size belt.

Part number is Duralast 231036.  Cost is about $13-15
if memory serves,
while just a replacement bearing for your old pulley is more
like $25, and
you haven't started paying machine shop costs.

Changing the
belts first will determine if you need the pulley.  If you
don't, just return
it.  And if you do, have it in your hands and install
that next.

There, you
fixed it.
:>)

Mike

_______________________________________________

Detomaso
Forum Managed by POCA
Posted emails must not exceed 1.5 Megabytes
DeTomaso
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References

   1. mailto:detomaso-bounces at poca.com?
   2. mailto:MikeLDrew at aol.com
   3. mailto:detomaso at poca.com
   4. mailto:MikeLDrew at aol.com
   5. mailto:MikeLDrew at aol.com?
   6. mailto:cengles at cox.net
   7. mailto:detomaso at poca.com
   8. mailto:hoppe1 at cox.net
   9. mailto:DeTomaso at poca.com
  10. http://poca.com/mailman/listinfo/detomaso_poca.com