Mr. K., son has 1997 Buick Lesabre, 189,000 miles. Lately, the volt light on dash has been coming on after driving a short way. Alternator shows a reman date of 2017, and appears new, from lack of grime on casing. Voltage, when read at Autozone was 13.5, when engine on. After a short,8 mile trip, When read with multimeter, at home, charge at battery was 12.26v, volt light was on. I noticed the casing on the alternator was very got to touch, but, I don't have a temp gun to measure. It seems very high. Will high temps kill, or, reduce an alternator's output?
Alternators don’t really get grimy. But it sounds like it has a bad battery and it’s overworking the alternator. It will kill it eventually.
Could be bearings in the alternator going out causing friction and excessive heat. The battery should show about 14 volts with the engine idling and a little over 12 volts when stopped. Load test the battery, too.
