Multiple Alternator Failures
Vittorio.Bares at nuance.com
Sun Jan 6 15:12:51 PST 2013
Subject: Audi 90 with AAN conversion
Symptoms: Battery drains while running
n Checked the voltage at alternator (power post to chassis ground) only showing battery or power pack voltage
n Had the alternator tested, testers indicated "stator circuit is bad"
n Replace the alternator with one that actually was supposed to go to an Alpha Romeo - but had the same size and was 115AMP and all mounting points the same - only, the capacitor (??) on the back was switched from the old to the new (I don't know what that is or what it does)...
n Put the new one in, measure voltage at the alternator, 14+ volts - seems like all is well.
n Run it a day or so, then it starts making a noise (luckily in the driveway), and soon after stops producing voltage.
n 2nd (same part no.) alternator is installed, capacitor (??) or whatever it is , is switched from one to the other and re-installed.
o Now on this one, I can't be sure if it was good or not, it measured over 13Volts - but I can't recall if the battery pack was on it or not...
o In any case - it's now dead as well.
n I've checked to make sure the blue wire is working
o Ignition on, batt light is on
o Motor running, batt light is off
o I also took a bulb and put it across from the battery post on the alternator to the blue wire post (b+?) and it also worked in the same manner.
n I've check the grounds. We cleaned up the grounds to the motor from the chassis.
o Also, checked voltage from different grounds - all the same.
Does anyone know what that capacitor (??) wire is on the back and if it could effectively kill the alternator in anyway?
I think our next step is to just get an S6 alternator - but interested to see if there is anything else that may be killing these alternators...or maybe, just dumb luck that we got 2 bad ones in a row?
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