On many modern cars, it is almost impossible to replace headlight bulbs on a DIY basis because of the very cramped conditions in the engine bay. In some cases, the battery and/or other components have to be removed, while in many other instances, the entire headlight assembly has to be physically removed from the vehicle to gain access to the bulb. In these cases, the better option would be to have the bulbs replaced by professional mechanics.
However, for the purposes of this article, we will assume that access to the bulbs is possible without having to remove anything, so below is a step-by-step guide on how to replace your own headlight bulbs.
Locate the wiring that leads into headlight. The wiring will often pass through a protective rubber cap, which has to be pulled off the back of the headlight assembly to gain access to the bulb holder. Remove this rubber cap, but note its position, since they often only fit back on in a particular way.
In almost all cases, there will be three wires that are connected to the bulb with a plastic connector. Be careful when detaching the connector since in many cases, the connections can be extremely tight. Excessive force can damage, or even destroy the spring clip that holds the bulb in place in the headlight assembly. Apply a steady force, and move the connector from side to side slightly while pulling it off the bulb, but avoid sudden, violent movements that could damage the bulb holder.
With the wiring detached, take a moment to look how the bulb is held in place. In some cases, there might be an intricate spring clip that hooks onto the headlight assembly in a certain way. In other cases, there might be small screws, so before you do anything, make sure you know how the bulb is held in place. At this point, it might be a good idea to take several clear pictures for future reference.
This is important since in some cases, you will not be able to see the indentations and notches that determine the bulb’s orientation in the holder. All bulbs fit into the holders in a certain way, which makes it important to have pictures to refer to if you cannot see how the bulb fits.
Remove the old bulb from the holder, and fit the replacement without touching the glass part. The oil on your skin will stick to the glass, which will cause that part of the glass to heat up more than the rest, which in turn, will drastically reduce the life of the new bulb.
Replace all retaining devices in the exact reverse order of removal, and made double sure that nothing can come undone by checking that all screws are tight, and that the spring loaded retaining clip is properly hooked into place.
Re-attach the plastic wiring connector, and replace the protective rubber cap. Make sure this cap is securely in place to prevent dirt and water from entering, or coming into contact with the wiring. Switch on the headlights, and check that both the high-and low beams are working.
Helpful Hints and Tips
- If you accidentally touch the glass of a new bulb, use an alcohol-based solvent to clean it.
- Since the brightness of bulbs decrease over time, always replace headlight bulbs in pairs to ensure that both lights shine at the same level of brightness.
- Resist the temptation to buy tinted headlight bulbs, since they might be illegal in your country, even though they are widely available.
- The best quality headlight bulbs are those sold at the authorized dealer. Many aftermarket bulbs that claim to be brighter than OEM equipment do not last as long, and besides, the best aftermarket bulbs available are less than 10% brighter than standard bulbs.
- If your car still uses sealed beam-type headlights, and you have replaced them for whatever reason, always have the lights reset at a reputable repair shop to ensure the lights do not blind oncoming drivers, and that they illuminate the road correctly to ensure proper vision at night.