You have to ask yourself why did I replace the battery? Was it doing nothing when you turned the key? It may be the starter. What does your dome light do when you hit the switch with your new Battery? Ok, first off make dang sure you have a good connection from your new battery, that means Cables are NOT corroded and you have a good connection and a good charge in the Battery. The ign. switch is used as a low voltage switch that sends juice to another switch called a solenoid, that is a switch also but it kicked over some heavy amperage that would fry your key switch, if you can imagine having you battery cable hooked to it. The soleniod transfers the battery directly to the starter. If you know anything about starters, you know that you can bypass the solenoid to test your starter(dont stand in front of a manual shift car and do this in gear) If you have a set of jumper cables and you hook the red lead to the big post of the sarter, and then the black lead to the engine or frame, then hook the other ends red lead to the battery post marked posative, and the black lead to the negative, you will envoke some sparks and if your sarter is ok the thing will kick like a stuck pig, or if its bad you will get nothing but the spark. If the starter is good but the solenoid is bad, the sarter will spin real quick and not engauge the flywheel. If everything works, then your battery cables need replaced!