Originally posted by RoadRunner:

This is your alternator telling you that the brushes are just about worn out.

At high RPM, the brushes are worn and the springs holding them in place
are just about fully extended and they aren't applying as much pressure
to the brushes as they did when the brushes were new.
At high rpm, the extended springs allow the brushes to bounce and float
above the stator and not make contact.
When this happens you get your alternator light on your dash.

My alternator did this at 90,000 miles and I replaced it.
No more problems.....




To add to this, replacing the brushes only probably wont fix ti becuase when these alternators start doing that, the contact area the brushes brush against get out of round, causing the new brushes to have the same problem. -Nick

"Moore has also accused the American people of being the stupidest, most naive people on the face of the Earth. And after last weekend, he's got the box office numbers to prove it!"