Several days ago my battery light came on. It is on about 75%
of the time. I pulled the negative cable while the car was
running. It didn't stall as I thought it would, just idled a
bit rough. The battery gauge on the dash indicates it is
charging properly while driving at regular speeds. Any
thoughts on my condition? Time for a new alternator or some
other issue? Thanks, Bill

Submitted by woebegone@mind… on Sun, 10/14/2012 - 17:24

Not so much the electronics, altho that is a very good reason anymore.
The other is, the alternator goes full field, and shortly destroys itself.
Worked with generators, but never with alternators.
By all means have it removed and tested now.

Submitted by NE48-24099 on Fri, 09/28/2012 - 17:20

William, this is what I would do........
1) Measure the battery voltage with the engine off. Should be 12.5
2)Measure the voltage again with the car running. Should be 13.5-14.0. If not...
3) Check the tension on the alternator belt. If that is OK.........
4)Then have the alternator checked out.
However, as William said, do not remove the cables while the car is running. That test was good years ago when there was no computer/electronics in the cars.
Let me know how you make out.

Submitted by mfrank@westnet.com on Wed, 09/26/2012 - 06:08

I'd pull the alternator and take it to Autozone to test, this could be a weak diode. Not a good idea to remove battery cables when the car is running.