Re: '89 200TQ alternator (the conclusion)

[e6941tb@ix.netcom.com]

Hello, everyone.

Since neither mine, nor the collective wisdom of this list did not come
up with the diagnosis, I decided to buy a new Alt. Besides, the old one
was of a '81 vintage, and had allready been rebuilt once.
 
Here are the results of the homework:

almost every major player carries rebuilt Bosches. The 90a variety is
plentiful and cheap (~$110 avg.)
Our 115a, OTOH, is very hard to come by. They are available on a special
order only.
They are generally rebuilt either locally by some Joe Blow Electric, or
by Papa Bosch itself in Allemaigne, with the latter being somewhat
steeper in price, although allegedly more reliable.
The prices, quoted to me, were as follows:

Pep Boys: $171 local, $280 Bosch, (both special order only).
Nat'l Auto: $180 local, $320 Bosch, (both special order only).
Strauss Auto: $220 local only, (special order).

and the winner is:
my favorite local import parts place: $200 Bosch only (in stock).

Besides the rather obvious reasons to go with the factory rebuilt Bosch
unit for roughly the same price, there was one more consideration: Bosch
pays for towing for 2 years, if the rebuilt unit causes you to get
stranded.

Aah, one more thing. After the Alt replacement the faint whining noise,
that I had in my HiFi sys, is completely gone. 
As many long time listers know, I have an Alpine setup, capable of
producing about 0.5kw worth of Rakhmaninoff Piano Forte (when I am in a
really_bad_mood!), so any slightest imperfection in the installation
would have caused a substantial Alt whine. And so it did! I have spent
looong hours, carefully rerouting the wiring, running signal and power
lines on the opposite sides of the car, playing with the ground points,
trying different filters. BTW, that 11 channel active ±15db Alpine EQ
(aka Dancing Lights) does make any installation screw-up stand out with
a horrible high pitched whistle, and it is generally a real b*tch to
tune up.
All in all I managed to tune the sys fairly well, so that a very faint
Alt whine was heard only with a lot of electrical consumers turned on
(lights, defroster, seat heaters etc) and only when the volume was all
the way down. I just learned to live with it, taking it as an
unavoidable nuisance associated with this much power.

Surprise, surprise! The noise is completely gone now. I have suddenly
realized that the noise supressing capacitor on the old Alt was probably
bone-dry and did no supression at all! Jeez, why do we always have to
take the longest route possible instead of looking into the obvious
first. It's not that I did not know for what reason this capacitor was
installed on the Alt....After all those years in the industry :(
Now, wher is that box of 30000uf x 35v, that I had stashed somewhere in
my lab?....
Shoood work real goood!...

Igor Kessel
'89 200TQ