1. Battery terminals: Make sure the battery terminals are clean and free of corrosion. If they are corroded, clean them with a wire brush and baking soda solution, then rinse them with water and dry them thoroughly.
2. Ground wire: Make sure the ground wire is properly connected to the chassis of the car. If it is loose or damaged, clean it and/or replace it as necessary.
3. Starter relay: The starter relay is a small electrical component that is responsible for sending power to the starter. If it is faulty, it can prevent the starter from engaging. To test the starter relay, remove it from the car and connect it to a 12-volt power source. If it clicks, it is working properly. If it does not click, replace it.
4. Ignition switch: The ignition switch is responsible for sending power to the starter relay. If it is faulty, it can prevent the starter from engaging. To test the ignition switch, turn the key in the ignition to the "start" position. If you hear the starter relay click, the ignition switch is working properly. If you do not hear the starter relay click, replace the ignition switch.
5. Neutral safety switch: The neutral safety switch is a safety feature that prevents the starter from engaging if the car is not in neutral or park. If it is faulty, it can prevent the starter from engaging. To test the neutral safety switch, put the car in neutral and turn the key in the ignition to the "start" position. If the starter relay clicks, the neutral safety switch is working properly. If you do not hear the starter relay click, replace the neutral safety switch.
If you have checked all of these things and the car still won't start, you may need to take it to a qualified mechanic for further diagnosis.
