My car wouldn't start today, so i replaced the battery fine for a while now its doing the same thing (not starting). If the alternator is gone would it stop charging completely or is it gradual, cos when i put the multimeter on with the car running its at about 12.6 to 13v. i know 13.7 is normal. And sometimes it starts, but today on idle with aircon running it completely dies. What do you boys think? Thanks Pex