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how to make a car alternator into a generator? Answered

I have a car alternator that has 3 wires. The colors of the wires are white, black, and yellow. The alternator also has a pin at the bottem that says "Bat" so im guessing that goes to the negative terminal of the battery. I was wondering if some one could please tell me how to wire this alternator up so that when driven by a motor it will charge a 12 volt car battery. If you could please also add a picture of the wireing schematics that would also be very helpfull. I have looked all over the internet and could not find one site that told how to wire up the type of alternator I have.

4 Replies

steveastrouk (author)2012-06-25

What's the alternator from ?

Does this link help ?


Your "alternator" IS your generator, cars haven't had "generators" for 50 years.


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Thank you so much for your reply, sadly the website only shows how to wire 1 wire alternators mine has 3. Im not sure what the alternator is from but if you want i could Pm you the manufacturing info on the alternator.

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The link I sent clearly shows alternators with 3 wires.

Like Re-Des says, you need some energy to "excite" the alternator.

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Re-design (author)2012-06-25

You really do need to know what it came off of. It may or maynot have an internal regulator.

The terminal marked Bat probably goes to positive if it came off a negative ground car.

Here's a link that may help you.

One last piece info, an alternator won't charge a totally dead battery.  I needs some battery power to energize the alternator.

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