how do i know if my alternator is bad

1995 MAZDA MPV
12,000 MILES
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GORDIN
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  • 1 POST
changed the battery for a new one also changed the starter and gave it a tune up
Feb 26, 2012 at 7:36 PM
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CARADIODOC
  • ✓ASE Certified Mechanic
  • 34,321 POSTS
  • ASE Certified Mechanic
Why do you suspect it's bad? What's the symptom?

To test the system you need a load tester but you can start by measuring battery voltage with an inexpensive digital voltmeter while the engine is running. It must be between 13.75 and 14.75 volts.
Feb 26, 2012 at 9:15 PM
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