How do I test the alternator on a 1999 Pontiac Sunfire?

Answer:

Answer

Connect a voltmeter across the battery terminals without engine running reading should be around 12.8
With engine running reading should be 13.8-14.2 if you are getting these numbers alternator is charging battery
First answer by Baldfatguy. Last edit by Baldfatguy. Contributor trust: 2032 [recommend contributor recommended]. Question popularity: 4 [recommend question].