Q: What does it mean when my headlights won't come on?

Headlights are relatively simple circuits. You will want to check all components from the switch to the bulb. To perform these tests, you will need to have a voltmeter and understand how to use it. You will test for available voltage before and after the switch (You can also test switch function with an ohmmeter). You will want to check the fuses and or relays in the fuse box that relate to the circuit. You will want to inspect the power supply for shorts or a loose connection. If there has been any damage to the vehicle, you should automatically check what has to do with the circuit in that area. Continue to inspect for any visual damage or shorts in the circuit. If you have inspected all of these components and have not found the fault, you will want to inspect the bulbs and make sure they have not malfunctioned at the same time. It would be rare, but could happen. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.