84 533i battery charging problems

["Hamm, Darren" <hammd@xxxxxxxx>]

Has anybody seen a problem like this before?
The charging system light on the dash doesn't always go out when my car
is started.   I know the battery isn't charging when the charging system
light is on because I have drained the battery running the engine with
the charging system light on.  I think there is a problem with the wire
that goes to the D+ pole on the alternator.  The Auto Electric shop says
the alternator is performing fine.  The funny part is, sometimes the
charging system works fine, others it doesn't.  If I momentarily jump
the D+ pole to the battery positive terminal, the charging system will
work for a while.   Where should I go from here?  Thinking there was
corrosion somewhere in the wiring loom, I ran a jumper wire parallel to
the blue wire from just next to the fuse box to the D+ terminal on the
alternator.  Also I cleaned all the contact surfaces with a brass brush.
The only effect these changes have had is now sometimes the charging
system works rather than not working all the time as it did when the
problem began.    What is the typical weak link in this system?
 
I would appreciate any troubleshooting help.
 
Thanks,
Darren Hamm
hammd@domain.elided <mailto:hammd@domain.elided> 
--
to be removed from bmw, see /bin/digest-subs.cgi
or email "unsubscribe bmw" to majordomo@domain.elided