"Mine does it all the time, and the culprit is ALWAYS the rectangle twp wire plug on the alternator. Its a clip in plug. Doesn't fit to well as it has been taken off and put back on many times. Whenever the battery light comes on, I just wiggle that plug around and the light always goes off."
I am pretty certain that my alternator failed because of the loose plug you are talking about. A loose connection gives a false reading to the regulator and the charging rate changes.
A loose plug gives the equivalent to resistance = reduced power flow. Increased power demands can get pretty high depending on situation and create situations where the alternator is maxed out.
When my alternator failed it resulted in the alternator catching alight and I had a fire right next to the fuel filter !!!!!! I just pulled into a gas station to fill up with fuel and I could smell burning. I opened the hood and found the alternator on fire - I was real lucky in that I must have caught it just as things failed
. It was a ****** to put out and I used two of the gas stations dry powder extinguishers - water helped too.
Again, this is just my opinion, but for the cost of a new plug you might save your alternator from catching alight. I think the plugs are around $8.00 and they come on a pigtail ready to splice in the wiring.
Just a heads up - you need to attend to that plug and replace it.
Thanks
mariner