Ok here is the situation. We recently replaced the stock alternator in my 87 GT, the replacement is a Delco-Remy remanufactured alternator. The new alternator is doing the same thing as the old, overcharging and therefore frying the battery. We were reading both alternators charging at over 15.4 volts. Within a week of putting the altnernator on the BRAND NEW battery is barely able to start the car and none of the electronics workmwith the engine off. I've been told that the voltage regulator is built into the alternator on GM, so my question is, what else could be causing the alternator to overcharge?

The old stock alternator, it worked for you for a long time before it started over charging? Or did you purchase this car recently?

I purchased the car on the last week of July and It was overcharging when I bought it.

quote Originally posted by bishop144: I purchased the car on the last week of July and It was overcharging when I bought it.

I'm thinking the previous owner wired something wrong or there is a shorted out wire or bad ground. Sorry I dont know enough about it to help more, someone more knowledgable will probably chime in.

Here is arelated thread
https://www.fiero.nl/forum/A...050818-2-062729.html

[This message has been edited by 2.5 (edited 09-04-2014).]