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<blockquote data-quote="maylar" data-source="post: 566317" data-attributes="member: 541144">Measuring current isn&#039;t that hard, but applying 160 amps worth of load is gonna be a biatch.Understand that the alternator&#039;s current rating means it will maintain its output voltage from no load all the way up to its max rated current. After that it either drops voltage or smokes...With every light and accessory on in your car you&#039;ll be lucky to draw 60-80 amps.To measure the current you need an ammeter in series with the power wire. A 200 amp ammeter won&#039;t be easy to find.You can also use a shunt and your DMM. A shunt is a precision high current resistor. They&#039;re calibrated to have some amount of voltage (usually millivolts) across them at their rated current. Like these Simpson shunts:<a href="http://www.simpsonelectric.com/pdf/webpdfg/Shunts.pdf" target="_blank">http://www.simpsonelectric.com/pdf/webpdfg/Shunts.pdf</a>.. which will provide a low voltage that you can measure with your dmm.</blockquote>

[QUOTE="maylar, post: 566317, member: 541144"] Measuring current isn't that hard, but applying 160 amps worth of load is gonna be a biatch. Understand that the alternator's current rating means it will maintain its output voltage from no load all the way up to its max rated current. After that it either drops voltage or smokes... With every light and accessory on in your car you'll be lucky to draw 60-80 amps. To measure the current you need an ammeter in series with the power wire. A 200 amp ammeter won't be easy to find. You can also use a shunt and your DMM. A shunt is a precision high current resistor. They're calibrated to have some amount of voltage (usually millivolts) across them at their rated current. Like these Simpson shunts: [URL="http://www.simpsonelectric.com/pdf/webpdfg/Shunts.pdf"]http://www.simpsonelectric.com/pdf/webpdfg/Shunts.pdf[/URL] .. which will provide a low voltage that you can measure with your dmm. [/QUOTE]

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