Testing an Alternator
Thread Starter
Instructor
Joined: Jun 2009
Posts: 155
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From: Minnesota
Testing an Alternator
I was out the other day with my 1979 L350 and the battery was died on me. The motor would barely turn over, very odd so my wife and I went and grabbed a burger and something to drink. An hour later when I came back the engine barely turned over but it did start and I was able to get home.
Once home I threw my battery tender on the battery and it eventually charged up (I should have thrown my charger on it, not sure what I was thinking). So now I am thinking it is my alternator and wondering how I can test the it to determine if I need to replace it?
Anyone know how to test an alternator?
Thx
Paul
Once home I threw my battery tender on the battery and it eventually charged up (I should have thrown my charger on it, not sure what I was thinking). So now I am thinking it is my alternator and wondering how I can test the it to determine if I need to replace it?
Anyone know how to test an alternator?
Thx
Paul
Thread Starter
Instructor
Joined: Jun 2009
Posts: 155
Likes: 0
From: Minnesota
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
the tests that they do at auto zone and advance auto are really good and free, the tests even tell you if the diodes and phase are right.
Pro
Joined: Jun 2016
Posts: 567
Likes: 82
From: Auckland
if you don't get these readings at the battery check for them at the alternator just to be sure it's not a broken cable
