2002 olds alero replaced a dead battery with new battery started fine came back

Check the basics like fuel pressure and spark and report back. If it's cranking like normal you could have had something not related go out at the same time. Also, check over fuses like the fuel pump fuse. Alex

IF you mean the starter motor is not 'cranking' the engine - I'm thinking there are two “piggybacked” positive battery cables - these tend to become corroded between the two battery terminal ends - remove negative cable first - then the positive cables - *throughly clean all cable connections* - re-install cables in reverse order.