I couldn’t find much online on getting some tips on replacing headlightsl bulbs on the Mercedes-Benz A-Class so, I’m writing this post as a quick hints and tips guide.
To start, an A-Class that has standard halogen bulbs, the dipped headlights are H7 type. To access the headlight unit holding the dipped headlights, you have to go underneath the wheel arch and search for an access hatch on the wheel arch lining. Once you open the wheel arch lining hatch, you can then turn the circle lid to open up the weather sealed headlight hatch to gain access to the bulb itself. You shoudl see something like this now.
Now, you see those screws? They are deceiving, you don’t need to touch those at all. All you have to do is twist the bulb conector anticlockwise and the bulb is unlocked from the unit.
Next stagebit to disconnect the wired connector from the bulb itself, just a small pull and your just left with an empty connector.
Now it’s just a case of putting it all back together after the new bulb is in.
Hopefully some of these photos help you to picture the process. The only think i found that was quite difficult was to close the hatch on the wheel arch lining. There is not much room to replace the hatch as you have to try and do this from the bonnet side.
The bulbs I installed were Philips X-tremeVision. This is a photo showing OEM bulb on the righy with the Philips on the left.