Car was in the body shop (minor rear bumper damage) and i suspect the shop guys killed the battery. it started ok but on the 2 mile drive back to work the radio started cutting out and the A/C fan cut off, also found the electric power steering was out when turning into the parking lot. Turned the car off and w/n start, battery was below 12V and w/n crank the starter but still had enough to work windows and stuff. Put a new battery in the next morning, put my meter on the battery and initially the battery was not charging but after bringing the rpm's up to about 2k the voltage jumped to over 14V showing the alternator was ok. everything looked ok going home after the car sat all day until after about 15 minutes the Battery light came on. i turned off the radio and A/C and continued to drive another 30 minutes home with the battery light on. I checked the charging voltage again and the battery seems to not be charging now, new battery is holding ok but there is no charging voltage. The car does not have IBS but i have read somewhere in this forum that the computer controls the voltage regulator, is there something that needs to be reset, i really don't want to change the alternator.

Thanks,

 

Start the car and let it run for a little bit. While the car is running, remove the negative terminal. if car turns off, you need an alternator.

 

That is NOT a good way to test your electrical system on a modern car. Anything before 1974 or so, yes. Sorry, but electronics have advanced over the years, and disconnecting or re-connecting can cause a voltage spike. This voltage spike may kill many black boxes that control your vehicle, like ECM and other black boxes on newer vehicles.

 

You could be right! At least it worked for me on my minis. Not only once :-)

 

Shouldn't have to rev to 2K to get the alternator to charge. Once the car is running even with everything on, voltage should not drop below 12v. I would suspect you're alternator is going. It's been my experience that they go over a short time and you will get warnings like you're getting now. As far as changing the alternator, about a 2hr job. Front end service mode and slide everything forward. Three bolts on the unit, presto chango, good to go.