92 Z24 stalling

Hello Just recently bought a 92 cav z24 that had symptoms of a dying alternator. She runs fine and then just stalls out with no electrical, battery light coming on just before dying. The battery is new and holds charge,and I just replaced the alternator. But it still has the exact same problem. If I charge the battery it starts great runs for a while and dies. then won't restart as there is no eletrical. Any ideas guys.....????? Any help would be appreciated.

the alternator could be bad. If you got it at pepboys it probably is

thx I'll test it