There are a few reasons why your car might not be starting when you turn the key, but the lights work. One possibility is that the starter motor is faulty. The starter motor is responsible for cranking the engine, and if it's not working properly, the engine won't start. Another possibility is that the ignition switch is faulty. The ignition switch is responsible for sending power to the starter motor, and if it's not working properly, the starter motor won't get the power it needs to crank the engine. Finally, it's also possible that the battery is low or dead. If the battery doesn't have enough power, it won't be able to provide the starter motor with the power it needs to crank the engine.
If you're able to start the car by slamming the door, it's possible that there's a loose connection somewhere in the wiring. When you slam the door, it may be causing the connection to vibrate and make contact, which would allow the starter motor to get the power it needs to crank the engine.
If you're not able to start the car by slamming the door, you'll need to take it to a mechanic to have it diagnosed. They'll be able to determine the exact cause of the problem and get it fixed so that your car starts properly again.
