What should you try first if your headlights fail?

When your headlights fail while driving, the first step you should take is to use the dimmer switch. This is a common issue, as sometimes the headlights may not work due to a simple adjustment rather than a complete failure. The dimmer switch controls the brightness of the headlights and can occasionally be accidentally turned down or off, resulting in them seemingly "failing." By toggling the dimmer switch, you can determine if the headlights will turn back on, which can help you avoid more complicated issues or the need for repairs.

While checking the battery power is also important in diagnosing electrical issues, it generally comes after verifying that the basic controls are functioning properly. Replacing the bulbs while driving is not safe and is not a practical solution. Pulling over and calling for assistance could be necessary if the headlights do not work after checking the dimmer switch, but it is not the first action to take in this scenario. Start with the simplest potential solution to address the problem before escalating to more severe actions.