alternator testing
-
nicklikesmilk
- Posts like an LN3

- Posts: 500
- Joined: Thu May 22, 2008 9:27 pm
- Year and Trim: 98 Oldsmobile Intrigue
- Location: Whitewater, Wisconsin
alternator testing
is it possible to test an alternator with just a handheld multimeter? my friend's car is having electrical trouble and i'd like to pinpoint the problem
1993 Park Avenue
200k, well-optioned, and running strong
200k, well-optioned, and running strong
-
Black Pearl
- Posts like an LG3

- Posts: 345
- Joined: Fri Jul 24, 2009 7:50 pm
- Year and Trim: 2002 SSEi
- Location: STC, MN
Re: alternator testing
You could see if it's putting out 14 volts. The right way is to take the car and have a load test performed, that will tell you if it works under load.
-
markwb
- Retired Gearhead

- Posts: 2572
- Joined: Sun Jun 01, 2008 5:41 am
- Year and Trim: 2003 SSEi
- Location: Groton, CT
Re: alternator testing
A quick check is to connect a digital voltmeter across the (+) & (-) battery terminals to monitor battery voltage. Start the engine, allow voltage to stabilize after a few moments, it should be approximately 14.0 VDC. Have another person in the vehicle help out. Have them turn on some accessories like the Rear Window Defroster, Headlights, A/C etc. while you're monitoring battery voltage. The voltage will dip slightly at first with the loading on the electrical system then it should begin to increase again indicating that the alternator is delivering charge current.
Mark




