PERFECT SIGHT | Accessories – Lighting

How regularly do you check the lights on your vehicle with a front and back walk-around?

The importance of seeing and being seen appears to be lost on some drivers that head out at night with defective or underperforming lights on their vehicles. The standard headlamps fitted to vehicles are a starting point when it comes to night vision and any failure has a direct effect on your safety.

Daytime running lamps save lives by identifying a vehicle on the road to other road users. Those that travel extensively at night should also consider adding extra driving lamps, but before taking that step it’s important to firstly check that every light fitted to your vehicle works correctly.

The normal headlamp globe fitted to new vehicles by the vehicle manufacturer is usually a long-life performer, aiming to maintain efficiency for a longer period rather than providing the highest possible light output. Regardless of the manufacturer, all halogen performance globes achieve their extra light output by being pushed beyond their normal operating tolerances. Without introducing design changes to the globes, they would face a severely reduced life, possibly only lasting for several hours or even minutes.

Performance globes compensate for the additional load on the filament by introducing special gases such as xenon into the glass bulb to protect the filament from premature failure. While this protective measure is effective, it will still not have the same life expectancy as a standard halogen globe.

Another vehicle design consideration is voltage. Alternator output tends to vary amongst auto manufacturers. Many modern cars and trucks with additional electrical loads from advanced multimedia and infotainment systems and other on-board computers are typically equipped with alternators that produce higher voltages. These higher voltages are often required for this equipment to operate correctly; the downside is that as performance globes are already operating at higher end tolerances, even small increases in voltage can lead to blown globes. To put this in perspective, a 5% increase in voltage can reduce the life of a globe by up to 50%.

Excessive heat is the enemy of most automotive components, and, in the case of performance globes, the heat build-up in the headlight can increase the filament temperature leading to reduced life. Unfortunately, modern cars are normally equipped with smaller, encased headlights that make it more difficult for heat to dissipate efficiently. Space within the engine bay or body of the vehicle is also limited, further adding to the issue. Automatic headlamps might be convenient, but lights turning on and off as a vehicle enters a tunnel, multilevel carpark or even in cloudy conditions can potentially reduce globe life. Every time headlights are activated, a short-term ‘surge’ is experienced by the globe during filament heat-up. The greater the number of on/off cycles, the increased likelihood that globe longevity will be compromised.

A problem particularly for vehicles that regularly travel rough secondary roads is vibration. The vibration from corrugated roads and rough surfaces will influence most of the vehicle’s components, including the delicate globe filament. Vehicles with firm suspension set-ups and low profile tyres can also experience the same predicament, with every bump on the road surface being felt, even on sealed roads.

It’s recommended to wear gloves when fitting any type of halogen globe, or at a minimum to avoid directly placing bare skin on the glass section of the globe. When turning on a halogen globe, the glass needs to absorb much of the resulting heat, evenly. When the glass is touched during installation, the residual oil from fingers creates a ‘hot spot’ on the glass surface, resulting in uneven heating. If the glass doesn’t heat evenly, areas of the glass will be prone to higher mechanical stress resulting in eventual cracking. When replacing globes, it’s always recommended to do so in pairs, to ensure even light dispersion.

A loose terminal connector on the rear of the globe can result in intermittent operation, with greater consequences than occur in the automatic headlight scenario. Faulty relays can also have a similar impact, so get this checked-out as soon as possible if you experience any intermittent light issues. Additional heat generated due to the bad connection can also transfer to the filament adding to concerns.

The life of a performance globe will vary, depending on the brand selected and the factors discussed above. As with many purchases, ‘you get what you pay for’, with the premium brand products normally providing greater performance and longevity than cheaper parts. The globe variant selected will also play a role. From H7-type globes you might expect around 550 hours of performance, while for H4 globes that feature a dual filament, up to 900 hours is achievable.

Ultimately, a driver needs to make a decision about how important additional light output is to them. It is not realistic to expect that performance globes will go for years without replacement, hence it’s important to consider replacing globes as part of the ongoing vehicle preventative maintenance schedule, with the same consideration as oils, fluids, filters and brake pads. With a disproportionate number of accidents happening at night, more light can be the difference between getting home safely, or becoming a statistic.

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