VW GTI Alternator Problems (fwd)

[Phil Ethier <ethier@freenet.msp.mn.us>]

Mayby you can help this VW owner.  DO NOT AUTOREPLY.  Send your reply to 
vitacco@bnr.ca
not to me.

---------- Forwarded message ----------
Date: Mon, 25 Sep 1995 16:11:00 -0400 
From: mark (m.) vitacco <vitacco@bnr.ca>
To: autox@autox.team.net
Subject: fw:VW GTI Alternator Problems 




Fellow Auto Cross'ers

I wounder if some of you can offer opinions on a re-occuring problem I'm
having with my 1984 DSP GTI.  I'm cooking alternator diode just about
every three months.  From the considerable service records that came with
the car, I am reasonably certain the origional unit lasted 140K miles.
I replaced it with a Motorola unit purchased (at considerable cost) from
the local VW dealer. This was replaced twice under the parts warrente
(again with a reconditioned Motorola unit). I then purchased a BOSH unit. 
Replaced it with a second unit (under warrentee) after obout 90 days, now
just had it fail Sat night (causing me to miss a event...RATS!) almost three
months to the day it was installed! (in case you are countint that is
the origional unit, two Motorolla's and two BOSH units so far). Needless
to say, I now can R&R alternators in about half the "flat rate" time!


I had taken the last three apart, and the diode checked open  both directions
on the ohm meeter, they also physicall appeared to be "cooked". I have
not jump started anyone or done any "arc welding" with my battery terminals.
Car always shows 10 volts when started and jumps up to 12.5 to 13.5 when
running.
 
My "theory" is  too much current via frequent high RPM operation. This car
has been autocrossed just about every weekend for the past year plus some
School and Time Trial (SOLO 1) activity. It spends a lot of time at 4000
to 6000 RPM.

Does this sound feasable? Any other ideas on what to look for in trouble
shooting?  Is anyone aware of a larger diamater pulley that could be
used to slow things down that will fit the VW (long) alternator shaft?
This is a Factory AC US model A1.

So we don't dont flood the net, please respond to me personally, if/when
I find the cause of this, I'll post a note. Thanks in advance.

Cheers

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+         .........                                                          +
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+  /       CORVETTE      /                                                   +
+ /........       ....../       Mark D. Vitacco         919 991 8699         +
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