87 4000cs Alternator failure? (Nolan Gilliam) rukshawmaster at msn.com

[Huw Powell]

> While I'm driving i notice the volts output is really low again and
> the stereo starts to cut in and out. So obviously its not a bad 
> battery...Does this sound like an alternator issue? Faulty ground?

Brushes worn down on voltage regulator.  They can be replaced if you're 
handy, or the whole unit can be.  It is screwed onto the back of the 
alternator.  Start soaking its little mounting bolts with penetrant now, 
one of them tends to rust weld itself into place because it's also the 
VR ground.  It's also nice to have a couple of new bolts for 
reinstallation, stainless is great here.  I forgot again what size they 
are...

Busted or loose alternator belt.  Pretty easy to check.

Broken or corroded "exciter" wire to alternator (it's the smaller, blue 
one).

Unlikely but possible, fried alternator (windings, diodes, etc.)

While it almost certainly is not just a "bad ground," all of these 
circuits could use a little cleaning once every ten or twenty years.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/