is Alternator kaput??

avim avim at
Thu Apr 24 20:06:10 EDT 2003

The VR of a 90AMP and the VR for an 110AMP alternator are exactly the same!
You have a different problem!

Your alternator IS NOT charging due to another problem.

Take care,

-----Original Message-----
From: quattro-admin at [mailto:quattro-admin at]On
Behalf Of siambisg at
Sent: Thursday, April 24, 2003 12:56 PM
To: quattro at
Subject: is Alternator kaput??

I mistakenly put in a new 90amp voltage regulator onto a 110 amp alternator,
and the battery is not being charged.  I have 2 main questions:
1.  Did I destroy the 90amp voltage regulator by running the engine at idle
and revving it a couple times?

2.  Considering the implications of question 1, is it likely the alternator
is kaput and needs a rebuild beyond the voltage regulator?  (i.e., would the
lesser voltage regulator prevent the otherwise proper function of

Tuesday night (after running my seat heaters on high frequently) my 88 90q
barely made it home with the battery warning light on and the idiot lights
on the dash on as well.  I pulled the voltage regulator off and found the
brushes badly worn (4mm & 2-3mm).

I've now replaced the voltage regulator with a new bosch unit, but when i
turn on the ignition the battery idiot light does not come on, and with
engine running the voltage on the battery reads only 12.14 volts or so.

The car has 208,000 miles on it so it's possible that the brushes &
something else in the alternator failed together.

George Siambis

More information about the quattro mailing list