The car wont start due to no crank, so I bought a brand new starter and installed it, but still no crank. The next step is to check out the ignition which would be my next suspection. Other than that, does anyone know what the problem would be? Or is there anything i can do to diagnose the problem?

p.s. the battery sometimes might not have enough juice inside to push the starter motor, which i will figure out shortly if thats the cause or not.