Headlights are an important part of car safety, especially when it comes to nighttime driving. If your headlight suddenly turns on and then shuts off, you may be left wondering what’s going on. This can be a perplexing and even dangerous problem. It’s important to pay attention to the cause and take steps to ensure that the issue is resolved.
In this post, we will discuss why headlights may turn on and then go out, and how to tackle the problem if it arises. We will also look at some basic maintenance tips that you can use to prevent the issue from occurring in the future
How do I know if my headlight relay is bad?
The headlight relay is basically a switch that uses low currents to control a higher current circuit. Most automotive relays are open, meaning the current does not flow until the relay is activated.
In a computer-controlled system, two relays one for the high beam and the other for the low beam control the headlight. Some vehicles also have a third relay that activates the daytime running lights
Here are two indications that your headlights relay is bad:
1. Headlights Don’t Turn On:
The first sign of a bad headlight relay is headlights that don’t turn on. A headlight relay will fail in the open position, preventing voltage from reaching the headlights. If the low beam headlight relay fails, the low beams will not work. Likewise, if the high beam headlight relay fails, the high beams will not work, and if then again if the daytime running light (DRL) relay fails, the DRLs won’t work.
2. Headlights Won’t Turn off:
Although it is rare, there are instances where a bad headlight relay can stick closed, stopping the headlights from turning off. The problem can happen in the circuits that supply power to the relay at all times.
Can a fuse cause one headlight to go out?
The electrical system in your car is protected with fuses. These fuses are designed to blow and break the circuit if much power comes through them. This way, it protects all the components on the circuit. When a headlight fuse blows, it could cause the headlights to stop working. Consult your manufacturer’s manual to locate the main fuse for the headlight circuit and replace the fuse with a new one having the same amperage rating. You can use a test light or a multimeter to identify the bad fuse without having to pull it out.
Potential causes of headlights turning on and then off
The problem described above about the lights going off and on is usually caused by the headlight bulbs overloading the light switch circuit breaker. I would recommend you replace the headlight bulbs with the factory-specified bulbs and then if problems persist then replace the light switch.
The likely cause of the headlight turning on and then off is the fuse, the headlight relay, the headlight switch, the dimmer switch or the wiring fault.
What to do if your headlight goes off and on
The first thing to do in this case is to retry the dimmer switch, which can be flexible between modes. If it does not work, you can use other lights such as parking, hazard, or turn signals to let other road users notice your presence on the road. Then you can find a place to park your car, inspect the headlights or call the automobile repair shop if necessary.
Risk of ignoring a faulty headlight
Most states have regulations requiring drivers to use their lights from sunset to sunrise. It’s also stated that all vehicles, except for motorcycles, must have two functional headlights. So, if you have a faulty headlight, it is likely that you will get pulled over.
Also, this can result in an accident that may cause property damage, injury, or even death if care is not taken. You might be lucky to see the road with only one working headlight, but if you drive like that, you could be pulled over and fined.
Driving with a faulty headlight is dangerous for you and other drivers. Because of this danger, it is illegal in all 50 states.
Conclusion
When you get into your vehicle and turn on your lights, you expect them to stay on until you turn them off. Unfortunately, this might not happen, sometimes, your headlamps will flicker on for a moment and then go out, leaving you in confusion and dread. If you’re in this situation, figuring out the cause of your headlights going on and then off can be difficult and often requires a professional to take a good look at your car.
Disclaimer
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