It seems I have the same problem. Light comes in every time RPMs exceed ~3300-3400.
I took a look to the Haynes Manual and they suggest to remove right driveaxle and unbolt Y-pipe from exhaust in order to remove alternator. Is THAT absolutely truth? I mean It seems to be NOT easy at all and very messy.
On ather hand in Ford Service CD there is no word about removal driveaxle and Y-pipes for the alternator access. Only rod-end.
Who is right? Anybody knows?
Thanks.