Possible Causes:
* Dead Battery: This is the most common reason for a car not starting. If the battery is completely dead, the starter won't have enough power to engage. You might hear a click or a weak buzzing sound.
* Faulty Starter Solenoid: The solenoid is an electrical switch that activates the starter motor. If it's faulty, it may not be sending enough power to the starter. This usually results in a buzzing sound.
* Bad Starter Motor: The starter motor itself can fail, causing it to spin weakly or not at all. This will also result in a buzzing sound.
* Corroded Battery Terminals: Corrosion on the battery terminals can prevent proper current flow, leading to a weak starter sound.
* Loose or Damaged Starter Cables: Damaged cables can create a poor electrical connection and cause a buzzing sound.
* Faulty Ignition Switch: A failing ignition switch can prevent the starter from receiving power.
* Low Engine Oil Level: Extremely low oil levels can prevent the starter from turning. This is less common but possible.
Troubleshooting Steps:
1. Check the Battery: Use a voltmeter to check the battery voltage. It should be at least 12.6 volts when not running. If it's lower, the battery may be dead or weak.
2. Check Battery Terminals: Clean the battery terminals with a wire brush to remove any corrosion.
3. Jump Start the Car: If the battery is weak, try jump-starting the car with another vehicle. If it starts, you'll need a new battery.
4. Listen Carefully: Try turning the key again and listen closely to the buzzing sound. If it's a consistent buzzing, it could indicate a faulty starter solenoid or starter motor.
5. Check Starter Connections: Check the starter cables for any loose connections or signs of damage.
6. Inspect the Starter Motor: If you suspect a bad starter, you can visually inspect the motor for any obvious damage. If you're comfortable, you can try tapping the starter motor lightly with a hammer to see if it engages. However, this is not recommended for most DIYers as the starter can be dangerous.
7. Consider Professional Help: If you're not comfortable diagnosing and fixing the issue, take your Expedition to a qualified mechanic. They can test the starter, solenoid, and other components to determine the root cause of the problem.
Safety Precautions:
* Don't try to start the car if there is a strong burning smell: This could indicate a serious electrical fault.
* Always disconnect the negative battery terminal before working on the electrical system.
* Be careful when working around the starter motor. It can be dangerous if it engages unexpectedly.
Remember, it's important to diagnose the problem accurately before replacing any parts. It's also a good idea to have your vehicle's history and repair records available.
