Are Your Car’s Headlights Repeatedly Burning Out?

Key Takeaways: 

  • Vibrations from a rocky road or worn-out tires can cause the headlight's filament to break. They also happen when the bulb isn't mounted securely..

  • Touching the headlights repeatedly causes hot spots to form on the bulb. The physical contact causes uneven heating, so use gloves when handling the bulbs. 

  • Leaving your headlights running for long results in extreme temperatures within the bulb, causing the filament to break. 

  • A crack in the housing can cause water to leak into the headlight, leading to short circuits.

  • Turning your headlights on before you start your car sends it into a rapid on-off cycle, damaging the headlights.



No one likes to change their car’s headlight bulbs repeatedly, but driving with burnt-out headlights can be quite dangerous. Driving at night or in extreme weather with just one or no headlights is hazardous as it reduces visibility. If you find your car's headlights repeatedly burning out, there are often many underlying conditions. 


Read on to learn why your car's headlights repeatedly burn out and how to prevent this from happening. 

5 Reasons Why Your Headlights Repeatedly Burn Out 

In this section, we discuss five common reasons why your car’s headlights repeatedly burn out..

Vibrations 


Halogen bulbs and sealed beam headlights contain thin tungsten filaments that emit light when heated. Even in optimal conditions, the filaments can break, leaving you in the dark. The filament's lifespan can be reduced by vibration caused by driving over rough roads, potholes, and bumps. However, this problem is more prevalent in older models. 


A faulty headlight structure can also cause vibration. If the bulb isn't securely mounted in the headlight assembly, it can vibrate, even during normal driving conditions. A bent bulb socket or insecure headlight housing could prevent you from mounting the bulb correctly. 


If the headlight housing isn't securely attached to the car, the entire housing, including the bulb and filament, can vibrate while driving. The housing can vibrate even if firmly attached to the car, such as when one or both front wheels are unbalanced. If you notice a shimmy in the steering wheel, this could be why your car's headlights repeatedly burn out. 


Touching the Headlight Bulbs 


Another reason why your car's headlights repeatedly burn out is if you're touching them directly. If the bulb's glass is touched barehanded, oil from the skin sticks to it and may cause hot spots on the glass during bulb operation. This results in uneven heating and can break the glass.


High-temperature headlight bulbs, including halogen and HID bulbs, employ a unique quartz glass envelope to tolerate high operational temperatures. When handling the bulb, wearing gloves or using a cloth or paper towel is crucial. 


Extreme Temperatures 


The headlight filament requires heat to produce light, but its durability decreases as the filament temperature rises. If you drive at night frequently or must use daytime running lights, your lights may be on longer. This, in turn, leads to a higher filament temperature that can cause it to break prematurely.


Driving in cold environments may also shorten your headlight's lifespan. Filaments become more brittle in low temperatures and are more prone to breaking. Paired with vibrations from rough roads and potholes, the filament is likely to break. 


Extreme temperatures can also affect the headlight lens or housing. High heat can cause the lens or housing to warp or crack, allowing moisture to enter the headlight and damage the bulb. In cold temperatures, the lens or housing can weaken, making it more susceptible to cracking or breaking if debris hits it.


Water Leaking into the Housing 


If you notice condensation inside the headlight, it's a sign that water has leaked inside the housing. Moisture buildup inside the headlight lens or housing can dim the light, but excessive cases can cause the headlight to fail.


Condensation inside the headlight can also cause damage to the bulb and electrical components. Moisture can create a short circuit or corrosion, damaging the electrical connections and causing the headlight to malfunction or fail. If cold water touches a hot bulb, it's more likely to break. 


A cracked lens or housing is usually why water leaks into the housing. If condensation occurs repeatedly, it is essential to investigate the issue to prevent further damage and maintain optimal headlight performance.


Furthermore, a cheap quality lens is more susceptible to cracks and damage, so ensure you’re using a high quality brand. 


Turning on the Headlights Prematurely 


Another reason your car's headlights repeatedly burn out is if you turn them on before starting the car. When you start your vehicle, it prioritizes the starter motor over other accessories by diverting electrical power.


If you have turned on your headlights before starting the engine, they will turn off and back on again, which can reduce the lifespan of the headlight bulbs due to the rapid on-off-on cycle. Ensure your headlights are off before you start the car to avoid this issue. 


Conclusion 


Headlights are essential, not only for your safety but for other people on the road too. If your car headlights repeatedly burn out, it could be because you didn't install them securely. Vibrations from a rough road and worn-out tires also contribute to this problem, so ensure you rotate your tires and drive on smooth roads.



We at Folsom Lake Honda offer the best car service to keep your car and its battery in the best condition. If you’re looking for a new battery, you can browse our inventory of car parts. For any queries, you can ask a professional through our 24/7 chat service on our website.