On Sun, Mar 27, 2011 at 1:41 PM, David Beierl <dbeierl@attglobal.net> wrote:

> At 03:36 PM 3/27/2011, Greg Potts wrote:
>
>> After all of this it appears I had a bad spare alternator. It looks
>> brand new but has been sitting on the shelf for a couple years and
>> my local rebuilder recommends against that. When I ground the blue
>> wire I get a light on the dash. My ammeter reads about .2A of
>> current when placed between the blue wire and ground.
>>
>
> I can't imagine why an alternator would go bad sitting on the shelf,
> but you have just described a correctly working ALT light circuit, so
> if the connection is good that puts it down to the alternator.
>
> But make certain it's not a subtle connection problem.
>
> Cheers,
> d
>
  A few days ago I took my 'extra' alternator to one of the chain  Autoparts
stores for their "free electrical testing" service.  We have O'reily's (used
to be Shuck;s) here in the Northwest.  The counter guy looked it up in his
book, then went to a fancy computer console/machine with it, and using a
touch screen...picked all the proper plugs and pigtails out of various
drawers.  He mounted it in the machine and it spun up, giving him readouts,
again according to the touch screen for that particular alternator (90amp
Bosch from a 93 2-liter Jetta)

  It took about 5 minutes total.  Free service.  I watched pretty closely,
expecting to be told..."Oh, sorry, this alternator is bad, but we have one
in stock that we'll sell you"   I also was curious to see if this counter
clerk actually knew anything...The machine mostly did everything for the
clerk..and it gave a readout according to the specs in the program for each
alternator...

  So I'm going to install that alternator into my van now, knowing it tested
good, rather than go to all the work of changing out my 'weak' one only to
find the Jetta one was faulty.

  Might be worthwhile to take your spare, or both over to one of those
Autoparts stores and get it tested..