I had trouble upgrading mine but since awhile ago now DC power and mechman makes h/o Alts i had to get mine from ohiogen also make sure to leave your headlights on when your banging around or else the alt wont put out all its power it will stop charging, matter of fact i did not believe this until i got some voltage meters i was sitting at 12.3 while lights was off once i turned them on few seconds later i was up at 14.5 i dont know if this is just a "cobalt" thing but i have heard of other new gm cars with the same thing just a heads up