The winter check of a car also includes the light test, with which the cars are safely on the road in the dark months.

The workshop not only checks the functionality of the entire lighting system, it also checks the correct height of the headlight cone and, if necessary, carries out repairs and adjustments.

The light test should be compulsory

Around ten million German drivers take the light test seriously every year and have it carried out as part of the winter check. Of course, the workshop also carries out an inspection in the meantime. The action is important, as can be seen when determining the defect rate: In autumn 2014, 32.9% of all systems were not completely in order. The inspecting vehicle workshops determined the following details:

  • In 10.4% of all vehicles, the headlights were set incorrectly (height of the light cone).
  • The taillight did not work properly in 8.6% of the cars examined.
  • Both main headlights had failed in 0.3% of all cars. Only one headlight was defective in 2.7% of the vehicles.
  • The brake lights were out of order in 4.0% of the cars.
  • Of course, the workshop also checks the indicators, low beam and high beam functions as well as the rear fog light.

The right light sources for the car

The type of light source used can also be checked as part of the light test, because standard halogen headlights often appear too weak. This applies above all to the H4 lamp, which can be replaced by an H7 lamp. Their amount of light is 1,500 lumens and thus 50% more than that of H4, which can still be found in the VW Beetle, the Mini or the VW Up. H7 lamps are not too expensive (rarely over 35 euros, mostly much cheaper). Choosing the right replacement lamp is so difficult that the layperson is advised to have it replaced by the workshop. This is also due to the sometimes very complicated changing of the bulbs, which requires partial dismantling of vehicle parts. But if a driver chooses lamps himself, he should rely on specialist suppliers, because scrap is also offered online, including unsuitable Far East copies. The light bulb used – H4 or H7 – is only part of the problem, by the way, the reflectors of the headlights are also very important.

Can halogen headlights be retrofitted with LEDs?

Specialist journalists from the FAZ investigated this question. The just named H4 and H7 lamps are halogen lamps, but LED or xenon lamps shine much brighter. However, these modern light sources are not cheap and are not available for many models. For some brands such as the Land Rover Defender, the Jeep Wrangler and the Mercedes-Benz G there are round seven-inch replacement headlights that can be equipped with LEDs. After the retrofit, the drivers enjoy bright white light with a sharp cone in xenon quality. LED lamps are known to last a very long time, and they also draw a little less electricity than halogen headlights. But the costs are very high, retrofitting – which is only possible on selected cars anyway – can cost between 700 and 1,300 euros. However, there are offers for inexpensive LED light sources that should fit in halogen sockets of almost all vehicles. For example, they are offered on eBay as complete kits at comparatively low prices (e.g. a pair for 170 euros) the halogen lamp and could last almost forever (promised service life up to 25,000 hours). The LEDs even have the E13 test mark and should therefore be approved. But the experts asked the TÜV and the Federal Motor Transport Authority, unfortunately with a negative result: TÜV Süd referred to § 49 StVZO, the KBA agreed with the judgment. These lamps are not approved. In addition to the E13 test mark, one of the additional numbers for vehicle lamps is missing, either R37 for halogen lamps or R128 for LED lamps. Such offers are Chinese products that are sold with an addition in very small print that the approval is not guaranteed. As a rule, providers even point out that they can only be used “beyond public roads”.