[DeTomaso] Alternator blues....

Mike Drew MikeLDrew at aol.com
Mon Oct 3 12:15:17 EDT 2016


Further to my further, here is a video I just shot after starting up and letting it run for five minutes. Rpm held at constant 2000. 

http://youtu.be/1T20MHyd9zU

Mike

Sent from my iPhone

On Oct 3, 2016, at 9:00, Mike Drew <MikeLDrew at aol.com> wrote:

> All,
> 
> Further to my original inquiry, I failed to mention that this is a GM alternator with built-in regulator, running in the stock three-wire configuration. Normally it works normally--shows a somewhat strong charge for a short time after engine start, coming back down to slight charge when battery is 'full' again, with slight discharge at idle when fans, lights etc are on. 
> 
> When it starts acting up, initially the needle bounces erratically over a small range between slight charge and slight discharge. After a few minutes of that, it goes into greater discharge mode as it quits completely. 
> 
> Mike
> 
> Sent from my iPhone
> 
> On Oct 3, 2016, at 8:15, "Himes, Terry (397C)" <terry.himes at jpl.nasa.gov> wrote:
> 
>>  Ditto.  I put in 2 rebuilt units and they both failed.  Finally bought
>>  a new one.
>>  No problem since.
>> 
>>  "A Purple Heart proves you were smart enough to hatch a plan,
>> 
>>   stupid enough to try it and lucky enough to survive!"
>> 
>>  Terry W. Himes
>> 
>>  JPL Jet Propulsion Laboratory
>> 
>>  Dawn Spacecraft Team
>> 
>>  Rosetta Sequence Team Lead
>> 
>>  Phone: (818) 393-6261
>> 
>>  Cell:     (818) 653-8213
>> 
>>  Fax:     (818) 393-3147
>> 
>>  [1]thimes at jpl.nasa.gov
>> 
>>  From: DeTomaso <[2]detomaso-bounces at server.detomasolist.com> on behalf
>>  of Julian Kift <[3]julian_kift at hotmail.com>
>>  Date: Monday, October 3, 2016 6:57 AM
>>  To: "[4]MikeLDrew at aol.com" <[5]MikeLDrew at aol.com>,
>>  "[6]detomaso at server.detomasolist.com"
>>  <[7]detomaso at server.detomasolist.com>
>>  Subject: Re: [DeTomaso] Alternator blues....
>> 
>>  Mike,
>>  I hate chasing these type of electrical problems, but here's some
>>  thoughts;
>>  i) Battery going bad (how old is it?), requiring the alternator to have
>>  to constantly charge
>>  ii) Some alternator re builders are notorious for units failing, over a
>>  50% failure rate is not uncommon. I had a similar issue with my GT40;
>>  on the third alternator we switched to a higher amp 'new' unit and
>>  never had a problem since.
>>  iii) It could also be an intermittent short or bad ground
>>  Julian
>>  ________________________________
>>  From: DeTomaso <[8]detomaso-bounces at server.detomasolist.com> on behalf
>>  of Mike Drew via DeTomaso <[9]detomaso at server.detomasolist.com>
>>  Sent: Sunday, October 2, 2016 9:11 PM
>>  To: [10]detomaso at server.detomasolist.com
>>  Subject: [DeTomaso] Alternator blues....
>>  Hi guys,
>>  Just got home from a terrific weekend in the Sierra foothills; 24
>>  Panteras
>>  (of the 36 scheduled) took part in the Niello concours at Serrano.   It
>>  heaved down with rain for a very brief period, but that rain then
>>  turned to snow
>>  which kept the large Reno/Tahoe contingent from braving the summit.
>>  Still, a great time was had by all who attended, and we drove home in
>>  splendid
>>  sunshine.
>>  We were driving in Lori's Pantera, which has a flat firewall kit and
>>  uses a
>>  GM alternator with built-in regulator.   She drove the car to Vegas
>>  this
>>  spring, and the alternator failed while we were there.   At first it
>>  started
>>  acting erratic, with the amp needle bouncing around, and then finally
>>  it quit
>>  and just showed a partial discharge.   Testing at the battery revealed
>>  it
>>  was doing nothing at that point.   We replaced it with another one,
>>  which did
>>  exactly the same thing and failed about 50 miles from home.
>>  We replaced THAT one, and the third one has worked fine until today.
>>  But
>>  it probably only has about 250 miles on it or so.   On the way home,
>>  once
>>  again, I noticed the ammeter needle behaving erratically, then it quit
>>  and
>>  showed partial discharge for many miles, then briefly came back to life
>>  and
>>  showed a very strong charge (since we had been running on battery power
>>  for
>>  awhile), then discharged again.
>>  Methinks the problem is not simply that alternators are failing, but
>>  rather
>>  that there is some sort of fault in the electrical system.   As
>>  electrons
>>  are far from my strong suit, I hesitate to start diving it to it
>>  blindly.
>>  What say all of you?
>>  FWIW we've got a spare alternator we will be installing tomorrow, which
>>  almost assuredly will work just fine...for awhile anyway????
>>  Mike
>> 
>> References
>> 
>>  1. mailto:thimes at jpl.nasa.gov
>>  2. mailto:detomaso-bounces at server.detomasolist.com
>>  3. mailto:julian_kift at hotmail.com
>>  4. mailto:MikeLDrew at aol.com
>>  5. mailto:MikeLDrew at aol.com
>>  6. mailto:detomaso at server.detomasolist.com
>>  7. mailto:detomaso at server.detomasolist.com
>>  8. mailto:detomaso-bounces at server.detomasolist.com
>>  9. mailto:detomaso at server.detomasolist.com
>> 10. mailto:detomaso at server.detomasolist.com
>> _______________________________________________
>> 
>> 
>> Detomaso Email List is not managed by POCA
>> Posted emails must not exceed 1.5 Megabytes
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>> 
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>> 
>> Members who post to this list grant license to the list to forward any message posted here to all past, current, or future members of the list. They also grant the list owner permission to maintain an archive or approve the archiving of list messages.
-------------- next part --------------
   Further to my further, here is a video I just shot after starting up
   and letting it run for five minutes. Rpm held at constant 2000.

   [1]http://youtu.be/1T20MHyd9zU

   Mike
   Sent from my iPhone

   On Oct 3, 2016, at 9:00, Mike Drew <[2]MikeLDrew at aol.com> wrote:

   All,
   Further to my original inquiry, I failed to mention that this is a GM
   alternator with built-in regulator, running in the stock three-wire
   configuration. Normally it works normally--shows a somewhat strong
   charge for a short time after engine start, coming back down to slight
   charge when battery is 'full' again, with slight discharge at idle when
   fans, lights etc are on.
   When it starts acting up, initially the needle bounces erratically over
   a small range between slight charge and slight discharge. After a few
   minutes of that, it goes into greater discharge mode as it quits
   completely.
   Mike
   Sent from my iPhone
   On Oct 3, 2016, at 8:15, "Himes, Terry (397C)"
   <[3]terry.himes at jpl.nasa.gov> wrote:

      Ditto.  I put in 2 rebuilt units and they both failed.  Finally
     bought

      a new one.

      No problem since.

      "A Purple Heart proves you were smart enough to hatch a plan,

       stupid enough to try it and lucky enough to survive!"

      Terry W. Himes

      JPL Jet Propulsion Laboratory

      Dawn Spacecraft Team

      Rosetta Sequence Team Lead

      Phone: (818) 393-6261

      Cell:     (818) 653-8213

      Fax:     (818) 393-3147

      [1][4]thimes at jpl.nasa.gov

      From: DeTomaso <[2][5]detomaso-bounces at server.detomasolist.com> on
     behalf

      of Julian Kift <[3][6]julian_kift at hotmail.com>

      Date: Monday, October 3, 2016 6:57 AM

      To: "[4][7]MikeLDrew at aol.com" <[5][8]MikeLDrew at aol.com>,

      "[6][9]detomaso at server.detomasolist.com"

      <[7][10]detomaso at server.detomasolist.com>

      Subject: Re: [DeTomaso] Alternator blues....

      Mike,

      I hate chasing these type of electrical problems, but here's some

      thoughts;

      i) Battery going bad (how old is it?), requiring the alternator to
     have

      to constantly charge

      ii) Some alternator re builders are notorious for units failing,
     over a

      50% failure rate is not uncommon. I had a similar issue with my
     GT40;

      on the third alternator we switched to a higher amp 'new' unit and

      never had a problem since.

      iii) It could also be an intermittent short or bad ground

      Julian

      ________________________________

      From: DeTomaso <[8][11]detomaso-bounces at server.detomasolist.com> on
     behalf

      of Mike Drew via DeTomaso <[9][12]detomaso at server.detomasolist.com>

      Sent: Sunday, October 2, 2016 9:11 PM

      To: [10][13]detomaso at server.detomasolist.com

      Subject: [DeTomaso] Alternator blues....

      Hi guys,

      Just got home from a terrific weekend in the Sierra foothills; 24

      Panteras

      (of the 36 scheduled) took part in the Niello concours at Serrano.
       It

      heaved down with rain for a very brief period, but that rain then

      turned to snow

      which kept the large Reno/Tahoe contingent from braving the summit.

      Still, a great time was had by all who attended, and we drove home
     in

      splendid

      sunshine.

      We were driving in Lori's Pantera, which has a flat firewall kit
     and

      uses a

      GM alternator with built-in regulator.   She drove the car to Vegas

      this

      spring, and the alternator failed while we were there.   At first
     it

      started

      acting erratic, with the amp needle bouncing around, and then
     finally

      it quit

      and just showed a partial discharge.   Testing at the battery
     revealed

      it

      was doing nothing at that point.   We replaced it with another one,

      which did

      exactly the same thing and failed about 50 miles from home.

      We replaced THAT one, and the third one has worked fine until
     today.

      But

      it probably only has about 250 miles on it or so.   On the way
     home,

      once

      again, I noticed the ammeter needle behaving erratically, then it
     quit

      and

      showed partial discharge for many miles, then briefly came back to
     life

      and

      showed a very strong charge (since we had been running on battery
     power

      for

      awhile), then discharged again.

      Methinks the problem is not simply that alternators are failing,
     but

      rather

      that there is some sort of fault in the electrical system.   As

      electrons

      are far from my strong suit, I hesitate to start diving it to it

      blindly.

      What say all of you?

      FWIW we've got a spare alternator we will be installing tomorrow,
     which

      almost assuredly will work just fine...for awhile anyway????

      Mike

     References

      1. [14]mailto:thimes at jpl.nasa.gov

      2. [15]mailto:detomaso-bounces at server.detomasolist.com

      3. [16]mailto:julian_kift at hotmail.com

      4. [17]mailto:MikeLDrew at aol.com

      5. [18]mailto:MikeLDrew at aol.com

      6. [19]mailto:detomaso at server.detomasolist.com

      7. [20]mailto:detomaso at server.detomasolist.com

      8. [21]mailto:detomaso-bounces at server.detomasolist.com

      9. [22]mailto:detomaso at server.detomasolist.com

     10. [23]mailto:detomaso at server.detomasolist.com

     _______________________________________________

     Detomaso Email List is not managed by POCA

     Posted emails must not exceed 1.5 Megabytes

     DeTomaso mailing list

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     [25]http://server.detomasolist.com/mailman/listinfo/detomaso

     To manage your subscription (change email address, unsubscribe,
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     Members who post to this list grant license to the list to forward
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References

   1. http://youtu.be/1T20MHyd9zU
   2. mailto:MikeLDrew at aol.com
   3. mailto:terry.himes at jpl.nasa.gov
   4. mailto:thimes at jpl.nasa.gov
   5. mailto:detomaso-bounces at server.detomasolist.com
   6. mailto:julian_kift at hotmail.com
   7. mailto:MikeLDrew at aol.com
   8. mailto:MikeLDrew at aol.com
   9. mailto:detomaso at server.detomasolist.com
  10. mailto:detomaso at server.detomasolist.com
  11. mailto:detomaso-bounces at server.detomasolist.com
  12. mailto:detomaso at server.detomasolist.com
  13. mailto:detomaso at server.detomasolist.com
  14. mailto:thimes at jpl.nasa.gov
  15. mailto:detomaso-bounces at server.detomasolist.com
  16. mailto:julian_kift at hotmail.com
  17. mailto:MikeLDrew at aol.com
  18. mailto:MikeLDrew at aol.com
  19. mailto:detomaso at server.detomasolist.com
  20. mailto:detomaso at server.detomasolist.com
  21. mailto:detomaso-bounces at server.detomasolist.com
  22. mailto:detomaso at server.detomasolist.com
  23. mailto:detomaso at server.detomasolist.com
  24. mailto:DeTomaso at server.detomasolist.com
  25. http://server.detomasolist.com/mailman/listinfo/detomaso


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