Q: The car won't start.

Hi there. Assuming that the battery is good, the connections are clean and tight, the replacement starter is good, the security light is turning off. There are several things that still can affect starter operation. If, the vehicle will start in neutral, the neutral safety switch could be the fault. The starter relay is another possibility The next thing to look at would be, the ignition switch. The ignition switch may not be providing a voltage signal, to the starting circuit. Given the range of possibilities for why the vehicle’s engine not turning over, I recommend you have your vehicle diagnosed and repaired by a certified technician from YourMechanic.