My car just left me stranded on the way to work. It's sitting in a parking lot as we speak. The alternator went again. The same signs I had last time. check charging system msg,ac on and off, and finnanly the car died in the parking lot. The car has a napa alternator on it with a lifetime warranty that I put on 8 mos ago for this same reason. so there's no problem getting another one but what the hell is killing my alternator?? The first time it did it I thought it was the battery and replaced that and of course it wasn't that. Put the meter on it and it's not charging. Yes I do have an asp crank pulley on it and I've added a stereo system but the first time it did this the car was bascially stock. Any advice please!! Also if I decide to go with the cobra upgrade alt (130amp) how much are they?,do they bolt right up? what's the part #? etc,etc