You had your altanator changed recently because the car would start but shut off minutes later but now that its a different altanator it won't star at all you dont know whats wrong?

You had your altanator changed recently because the car would start but shut off minutes later but now that its a different altanator it won't star at all you dont know whats wrong?
for 1 ure alt wudunt stop any car from starting unsless the belt broke in some cases that is. look at fuel first,then after that by the systoms u say ,id luk at crank sensor