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Old 09-17-2012, 12:01 AM
goat88 goat88 is offline
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Location: Wichita, Kansas
Join Date: Feb 2008
Posts: 182
Mein Auto: 1989 BMW 325I
Originally Posted by hornhospital View Post
Click the link that johnf posted and see what that says about the rotor of an alternator. It is NOT a magnet until it is energized by, guess what, the excitation voltage through it. And the test you got at Advance? Guess what the two wires to the alternator did before they started pulling current out of the spinning alternator? Yup...sent excitation voltage into it. Of course you'll get 14ish volts off a running alternator if you pull the wires. You already had it started with excitation voltage before you pulled the wires. An alternator's excitation voltage is self-sustaining once it's producing current.

I'm not trying to be an ass either, but I know alternators and electrical systems. I've been working on them for forty years.

Sent from my MB860 using Bimmer App
Well if you read the whole article on wikipedia regarding automotive alternators its says plain as day that they can self excite, the other "various sources" i used was to confirm that it was a true fact
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