test alternator
Post Fiend
Joined: Sep 2004
Posts: 5,231
Likes: 1
From: Near Fresno, California
Use a voltmeter - measure voltage at the battery before you start it, and again when the engine is running - maybe above 1500 or so RPM. Should read 12.6 or so before, and 13 to 14 volts when the alternator works.
Cheap voltmeters are not real accurate so just look for a volt or better increase when the alternator charges. Also, a low battery will draw the voltage down and will need to charge a while before you reach max voltage.
Cheap voltmeters are not real accurate so just look for a volt or better increase when the alternator charges. Also, a low battery will draw the voltage down and will need to charge a while before you reach max voltage.
