• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Testing an alternator

Share this page

Lin

Lin

Jedi Knight
Gold
Country flag
Offline
What do I need to do to test the output of an alternator?

The Bugeye my son and I have together ( I bought, I rebuilt, I maintain, I keep clean - university son drives and takes coeds for rides) is experiencing some charging problems.

We have a Lucas alternator (no jokes about that please) that has served us well for about 4-5 years. Thought I would check this and the battery first. Thanks as always.

Lin Rose
1960 BT7 in restoration
1959 Bugeye
 
Hi Lin,
The most simple check would be to connect a volt meter between the battery & ground. Engine off should read something like 12 volts. Engine running at fast idle should read around 14 volts.
D
 
Dave, Thanks for the response. I put a fresh battery in the car. The voltmeter showed 12.3 volts. After starting the car and reving to about 2,000, the battery reading remained the same. Is this test definitive? By that, I mean is the culprit definitely the alternator rather than some other component? I assume the answer is "yes" since the engine is running fine and all other electrical functions seem to be working properly.

Thanks again.

Lin Rose
1960 BT7 in restoration
1959 Bugeye
 
"Is this test definitive"?-Kinny Lin,But why not take it to an auto parts store and have them test it for you .Most of them are willing to test them for free.---Keoke- /ubbthreads/images/graemlins/cowboy.gif
 
Sounds definitive to me, take it straight to rebuilder shop.
 
Back
Top