My first response is to replace the alternator. It sounds like the brushes in the regulator are bouncing
at high engine rpm... it could be weak brush springs or a rough slip ring surface.
In response to the statement that a company checks their alternators to 7000 rpm.... If you do a little
bit of math... the Contour FEAD runs about a 2.7 to 1 pulley ratio to the alternator... 7000 alternator rpm equate to about
2600 engine rpm.
Just my 2 cents worth...
