Checking an Alternator

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Mar 18, 2003 | 07:47 PM

GeneStoner

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From: Great NW

Checking an Alternator

How can a Layman, without fancy equipment, check to see if his Alternator is making enough DC?

Mar 18, 2003 | 08:27 PM

steve83

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From: Memphis, TN

Checking an Alternator

With a voltmeter. Turn on the A/C, fan, & headlights with the engine running and see if you have 13.2-15.2V from the alternator output terminal to its case.

Mar 18, 2003 | 08:53 PM

Mike W

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From: Central Kali

Checking an Alternator

It won't produce it's rated amp output until a certain rpm is reached. Some were 5000 alternator rpm.

Mar 19, 2003 | 03:01 AM

GeneStoner

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Checking an Alternator

So, the negative post (black) of the ammeter is put on the case of the alternator (-) and the positive post (red) is put on the alternator output (+) terminal?

Just making sure...

Mar 19, 2003 | 03:24 PM

Franklin2

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From: Virginia

Checking an Alternator

Whatever you do, don't use an "ammeter" to do this check. I am hoping you might have just made a small terminology mistake and meant to say voltmeter. You 've got everything right except use a voltmeter on a scale that will read the voltage comfortably.

An ammeter is used to measure current, and is a dead short if you try to use it from the + to the - of case of the alternator.