'89 200TQ alternator

[e6941tb@gnn.com]

Hello, virtual club!

Well, it has finally happened to me. This Friday I brought my 200 back
home in a flatbed!

Last Thursday I had to fly out to Cleveland, OH, on business, so I
parked the car in Philly International, on the 5th (open air) floor of
the short term parking. When I returned the next day (around 16:00), it
was still pretty damp after that nasty weather they had in Philly on
Thursday. The car started fine, but the voltmeter showed no charge.
I, naturally, immediately killed all non-essential consumers (seat
heater, RR defroster, stereo, headlights, cabin heater) and headed for
home, hoping to make it on the battery alone. No such luck.

Speaking of one's luck: remember I posted a cell phone related question
several days ago? Well, I have cancelled my both cell accounts on
Wednesday, intending to open two new ones, with the new carrier, on
Friday (the cell sevice guy has my Mot 650 in stock, but is still
locating a Pan HB-70 for my wife).

Anyway, here I am, in a suite, white shirt and a tie, standing like a
moron next to a rather attractive red German car with the 4-way flashers
on and the hood risen, under the bridge on the portion of I-95, that
runs above neighbourhoods, not included in the tourists guides. And
although I still have the phone, mounted in the centre console, it is
deaf, mute and generally dead as of two days ago, on my own accord!
Needless to say, since I looked like a complete sucker, within minutes a
rusty Ford stopped next to me, and a dude with half of the front teeth
missing, offered me "help". When I politely declined and thanked him for
stopping by, he said: may be you have 3(!) dollars to spare, Sir? I got
so angry (hate voltures, especially the human ones), that just barked:
wrong line, pal! and walked away.
I also tried to use my CB, but the battery was only at 8v, and the radio
was intermittenly cutting out and clipping the sound. Double bummer! 

Anyway, this is what I know today:

First off, the following check-ups have been made (Bentley):
1. The excitation voltage (12v on the blue D+/61 wire) is present when
Ignition is ON.
2. The excitation current is 151ma (Bentley sez ~150ma).
3. The resistance between the blue wire terminal and the + Battery
terminal is 76ohms (Bentley sez <150ohms).
4. The voltage regulator works. I have swapped the regulators/brushes
with the Fox => the Fox still runs, Audi does not.
5. All the lights work(yes - the alt, ABS and brakes in the dash, as
well as the RR license plate illumination)
6. There is no output on the B+ terminal of the Alt.

The Alt is presently on the bench, partially apart, and the resistances
are as follows:

1. B+ to body - 10M (OK)
2. D+/61 to body - 26k w/Audi regulator on either Audi or Fox.
2a.D+/61 to body - 5k w/Fox regulator on either Audi or Fox.
3. The rotor (between the circular racers) - 2.75 ohm (seems OK, after
all, it's wound with a thick Cu wire)
4. The capacitor (on the ohmm range) shows a charge/discharge pattern,
typical for the electrolitical ones. I think that it is a plain paper
one, it's value is 0.22uf. Shouldn't it be showing infinity?

Since it has never happened to me before, here are my questions:

1. How can Rotor and Stator windings be tested for shorts in the
winding?
2. Can I test the diods without desoldering one terminal on each tested
diod?
3. Can a Capacitor go bad (dry out or have an internal leak), causing
the loss of Alt output?

I recall a thread on the subject several mos ago, but at the time did
not save it. May be the fellow(s), who posted it originally, would be
kind  to resend it to me. Steven, were that you?

OTOH, the alt on my '89 Audi is a (factory) remanufactured 110a unit of
a 1981 vinage!
Maybe it's just cheaper to get it rebuilt?
If so, what's the best place? Price range?

Or maybe I should buy a rebuilt one?
If so, what's the best place? Price range?

Thanks mucho!

Igor Kessel
'89 200TQ