I decided to go ahead and ditch the stock alternator in my S4 for a GM CS130. I followed the steps in this thread: http://www.nopistons...nator-solution/ to install it.



After spending a night getting it installed and wired, I went ahead and fired it up. It fired right up and the voltmeter on the dash jumped all the way to 16 volts, and it went up and down with engine rpms. As high as 16 and as low as 12 volts. It was night time and I had my headlights on, and they died. I kinda panicked and turned the car off. I checked all the fuses to see if had blown anything, and it all was fine to my surprise.



So I fired it back up and now I'm getting 12 volts with no surging. With the stock alternator I got something around 14 on the dash voltmeter, and this is way lower. It's still drivable, (thank God) but I don't have a clue where to start troubleshooting, or if I even need to troubleshoot. I just figured that I would see at least the same as stock voltage?



This is my first venture into car electrical aside from changing a headlight, so any help is greatly appreciated.

 

Can't edit my original post, so here is an update: Car died out while I was driving. had to get it towed to a shop. Hopefully they can figure out what is going on.