Why did the high beam suddenly stop working?
2 Answers
If the high beam suddenly stops working, the first thing to check is whether the high beam bulb has burned out, and then check if the fuse has blown. Cars are equipped with fuse boxes—typically, there are two fuse boxes in a car, one in the engine compartment and another in the cabin. The fuse box contains fuses that protect the electrical circuits. If the current in the circuit becomes too high, the fuse will melt to protect the circuit. High beams enhance the driver's visibility and expand the field of view. On dark roads without streetlights, the visible range with high beams on is much greater than with only low beams.
The other night while driving, I suddenly encountered a situation where my high beams stopped working, which really freaked me out. After pulling over to check, I found that a fuse had blown. Later, I learned this is actually quite common. Besides fuses, bulbs suddenly burning out is also a frequent issue, especially during the hot summer months. If you notice all other lights are working fine, it might be worth checking the high beam switch for contact issues. Wiring degradation is another thing to watch out for, particularly in cars that are five or six years old, as the wiring harness might have corroded. The most troublesome issue is a relay failure, which you can't fix yourself and requires a visit to a professional shop. Driving at night with malfunctioning lights is extremely dangerous. I recommend pulling over immediately, turning on your hazard lights to inspect the issue. If you can't identify the cause, it's safest to call for roadside assistance right away.
