Cheap 90A Bosch Alternator fix for all!!!

[Eric Maxon <emaxon@megsinet.net>]

I had, and shared, a VERY pleasant surprise last week:

One of my customers had a remanufactured Bosch 90A alternator in her '86
Coupe GT that was working intermittantly (sometimes had to rev the
engine over 2500rpm to get the alternator to start producing enough
current to keep its field coil primed!) due to totally worn out
brushes.  I was able to save her about $150 over the price of another
reman alternator by selling just a new brush/voltage regulator block for
$36.

  For alternators that go for less than $100 rebuilt, I think it's a
waste to replace individual parts like this.  But in this case, where
the Bosch reman unit retailed (at least at my shop... hell, list is more
like $240) for around $180, it's well worth it.  ***I found a rebuilder
who also happens to be a partial line Bosch WD-- and they STOCKED the
brush/Vreg block.  Not even my full Bosch line distributor had 'em, and
last time I tried to buy individual parts for a Bosch Alt., (A diode
block for a crummy old 60A Alt. from a 1980 Scirocco,) the bastards
(different rebuild shop,) wanted to charge me $60. (%80 of the cost of a
Bosch reman!!!)  They're my 2nd tier supplier, and they do quite a bit
of retail biz, so I'd be happy to send them on to the qlist. I have no
idea how/if they'd handle mail orders, but here 'goes:

A-Foreign & Domestic Inc.
2924 N. Western Ave.
Chicago, IL 60618
(773) 463-8555  "foreignautoelectric" = Chris, the owner.

"BOI 30062 Vol. Reg." was the notation from the invoice.  (I've already
trashed the box... sorry.. no Bosch or Audi part number, but it was a
bonafide Bosch part in a Bosch box)  Just ask for the voltage
regulator/brush "block" for a Bosch 90A alternator (standard on just
about every VW/Audi from the mid 1980's to present.)

Listen, these are the OLD style pictured in the factory manual, with the
brushes you can easily desolder/solder off/on, so NEXT time they wear
out (probably 20% sooner than the last set since you've not turned the
stator, you naughty boy) you can replace just the brushes for a measly
$5 at your local hardware store.  (Take the old ones and a micrometer
along!!!  As long as you find something close, you can sand them to the
exact dimensions with emery cloth or sand paper)

You can remove the brush/Vreg block w/o removing the alternator-- just
disconnect the battery and remove the two slot head screws from the back
of the alternator w/ a right angle blade screwdriver (wouldn't want to
accidently short across the B+ termanal w/ the battery connected now,
would we??)  New spec. for the brushes is 10mm protruding from the
plastic, (the longest edge) and min wear spec. is 5mm. I had two units
here at the time: one had 4mm protruding and worked fine, the other
(hers) had 3mm protruding and worked intermittantly.  So, when your
brushes wear to somewhere between 3-5mm in length, depending upon luck
and how many times your stator has been turned, your alt. will fail. 
Hell, for $35  (Okay, less if you're buying direct,) I'd keep one in the
trunk.

I hope this saves qlisters someone some $$$$


Eric, 
The Manicured Mechanic
"Never Gouges"
Chicago, IL.