Battery: Check the battery connections to ensure they are clean and tight. A loose or corroded connection can prevent the starter from receiving power. If the battery appears weak or dead, try jump-starting the vehicle. If the vehicle starts with a jump-start, the battery may need to be replaced.
Starter: If the vehicle does not start even with a jump-start, the starter may be faulty. The starter is responsible for turning the engine over when you turn the key. If it is not receiving power or is damaged, it will not be able to start the engine. You can try tapping the starter with a hammer while someone else turns the key to see if it will start. If it does, the starter may need to be replaced.
Ignition switch: The ignition switch is responsible for sending power to the starter when you turn the key. If the ignition switch is faulty, it can prevent the starter from receiving power. You can try turning the key back and forth several times to see if the engine will start. If it does, the ignition switch may need to be replaced.
Alternator: The alternator is responsible for charging the battery and supplying power to the electrical components of the vehicle when the engine is running. If the alternator is not working properly, it can cause the battery to drain and prevent the vehicle from starting. You can check the alternator by measuring the voltage across the battery terminals with the engine running. It should be around 14 volts. If it is significantly lower, the alternator may need to be replaced.
It is recommended to have your vehicle inspected by a qualified mechanic to accurately diagnose the issue and determine the appropriate repairs.