I just changed alternator and car wants to cut off and sometimes does, when the car is off the batt hovers at or around 12.6 volts. But then doesnt want to crank the next time i go to start it.

Do I need a new battery? Or is the Alternator still having issues somewhere?

 

it sounds like you don't have something connected good enough. LIke a ground maybe.

 

.

 

Fixed problem, replaced alt and batt.

 

what a horrible way to diagnose a problem

 

now take the positive cable off the batter and connect a test light between the cable and the battery.

does your test light come on?

if yes, you have a drain. and it will die again.