High voltage = bad alternator. The voltage regulator is going out. This is one of the most common ways that this alternator goes out. I would suggest finding a local rebuilder- look in the yellow pages, call independent shops and ask, and maybe even some nice parts guys will tell you who rebuilds automotive electrical parts locally.
If you do feel like you have to go purchase one from a parts store, then I would suggest getting the cheapest one you can buy, and keeping your alternator to have it rebuilt locally when you have time to find someone. 2 reasons for this: 1) it should be much cheaper, like $80 instead of $200. 2) Local rebuilders use better parts because warranty repairs hurt their cash flow more than large chain stores.
You can also check with Village Ford, our new OEM supply vendor, to see if they have a decent price on a new Motorcraft alternator. You'd probably have to wait a few days, and I wouldn't suggest driving the car with an alternator that is giving over voltage. All you have to do is spike up to about 18v, and all sorts of things will be killed. Keep in mind that all of those numbers you saw were actually .2v higher at the battery. You're also probably not doing the battery much good either.
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Originally Posted by the user formerly known as ZX3_Chick
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