Fwd: New alternator - No AM radio?

[Sandy Duffy <sandyduffy@home.com>]

>I have just had the alternator replaced on my 89 200TQW.  During this
>process the battery was removed for a bit thereby causing the radio safety
>features to activate.  FM works fine [as good as before ;-)] but the AM is
nothing but 
>static now.  

Matt 

There is nothing that was done (that I can see) that would change the
performance of the AM section of your radio. Essentially all you did was
remove the power from the radio and power it back up. I must assume you AM
is working but there's so much noise and "hash" being generated by the
charging system that that is all you can hear. (FM being much higher
frequency is largely unaffected) The key here I believe is the alternator
replacement.  There are only a few things that affect AM performance.  They
are:

1) The alternator is not well grounded due to corrosion in its connections.
 Most AM noise problems come from the lack of a good ground.  Check and
CLEAN all your wires and connectors that are associated with the
alternator.  Don't forget the battery connections under the seat.  What
LOOKS like a good connection may not be one because of corrosion.  Pull
every connector apart and clean it thoroughly. When you clean them make
sure each connection is shiny and free of oxidation.

2)There might have been a filter or capacitor on the old alternator to
remove the alternator "hash" that is common to the output of all
alternators.  Make sure your new one has one on it as well.  If it never
had one perhaps your old alternator had one installed internally.  These
things are available after market from Crutchfield or local car stereo
dealers.

3) Your new alternator has poor connections in the brushes (not very likely
but worth checking if all else fails)

Audis are fairly "noisy" cars.  The multiple computers generate noise and
the alternator generates noise.  I think in your case, if the AM was all
right before the new alternator, something changed when it was installed.

HTH

Sandy