how to change mercedes hid xenon headlight bulb

Mercedes HID Xenon Headlight Light Bulb Replacement DIY

Updated Tuesday Dec 12, 2017

Learn how to change Mercedes HID Xenon headlight bulb. Cost to change Mercedes-Benz HID headlight bulb varies between $85-$200 at most Mercedes dealerships and auto mechanics. If you like to save money, buy the HID bulb online and install it yourself in less than thirty minutes. This guide applies to 2005 and newer Mercedes models including E, C, S, CLS, G, GL, ML, R Class. For this repair, you will need a pair of D2S 35W HID Bulbs. While a bad HID Xenon light bulb is the most common reason why your Mercedes-Benz headlight is out there can be other issues as well including: 

  • Faulty HID Ballast 
  • Bad Ignitor
  • Blown headlight fuse. Each headlight has its own fuse.
  • Corroded headlight terminal
  • Defective SAM Module
  • Loose connection

How do you know if the Xenon bulb is the reason your Mercedes headlight is out? Typically a Xenon HID bulb will get dimmer and the light color may change to pink near the end of its life. If you noticed these symptoms then replace the HID Xenon bulb.

What you will need

  • D2S Bulb 35W
    • The most commonly used bulb on Mercedes-Benz cars. Check owner's manual to verify. 
  • Patience
    • This DIY requires patience. You will be working in limited space. Reaching the bulb can be challenging.

It is recommended to replace both bulbs at the same time for two reasons. First, HID bulbs have a certain lifespan measured in hours. Which means the other bulb will most likely fail soon. Second, the light color will not match your stock headlight bulb. 

Instructions

Removal

  1. Turn off the ignition and make sure the lights are turned off as well. 
  2. Wait 10 minutes. This will allow any residual voltage to discharge. HID bulbs operate at a voltage that is thousands of volts when the bulb ignites. Such high voltage can cause injuries or shock. 
  3. Access the back of the headlight. Remove the back cover by unclipping it. If you have a round cap, remove by twisting it counterclockwise. replace hid bulb mercedes

     

  4. Unplug the wire from the ignitor. mercedes hib bulb replacement unplug wire from ignitor S C CL class

     

  5. Remove the ignitor/ballast by twisting counter-clockwise and pulling it away. Note that on some models such as S-Class, this will remove the bulb as well. On other models such as the R-Class (R350/R500), the bulb will still remain in the headlight. Follow the next step to remove this bulb.how to change xenon headlight bulb on mercedes diy

     

  6. Press and squeeze the two tabs of the metal wire and unlock. Remove the HID bulb from Mercedes headlight. mercedes xenon bulb

     

Installation

  1. Place the HID bulb in the headlight. Make sure it is sitting properly and is pressed all the way. The HID bulbs have a couple of channels that need to line up properly in the headlight assembly. If the bulb came out with the ignitor then install the bulb on the ignitor instead. mercedes hid bulb diy

     

  2. Lock the bulb into the headlight. hid bulb locked in mercedes headlight

     

  3. Install the ignitor by placing it on the bulb and locking it in place. First, you need to line up the four tabs.mercedes ignitor locking tabsNext, twist it clockwise to lock it.lock bulb in headlight mercedes

     

  4. Connect the electrical wire by pressing it in the ignitor. Reinstall the cap and you are done.install mercedes headlight bulb hid xenon

     

Troubleshooting Mercedes-Benz HID light problems

I replaced the Xenon bulb on my Mercedes, but the light is still not working. What else could it be?

  • Faulty HID Ballast 
  • Bad Ignitor when applicable
  • Blown headlight fuse. Each headlight has its own fuse.
  • Corroded headlight terminal
  • Defective SAM Module
  • Loose connection

Check the fuses first. Each headlight has its own fuse on a Mercedes-Benz. If the fuse has not blown the next thing you need to check is the ballast. One way to check is to swap the ballast from passenger to driver side. If the problem moved to the other headlight, the problem is the ballast. Also, check the connections to the headlight for corrosion. It is not uncommon for water to get to it and corrode the terminal. In rare cases, the wires inside the headlight assembly may get damaged or melt as well. 

My headlight works fine then it goes out. Replaced the bulb several times already. What could be the problem? 

Make sure you are using the correct HID bulb. Don't use cheap HID bulbs. Ballast or igniter may also be defective. If it is the same bulb that goes out and then turns back on, the problem is not the bulb. It is usually the ballast or igniter or a SAM module. Once the bulb itself fails, it will not come back to life randomly.

Mercedes HID headlight flickers or flashing, why? 

At the end of its life, an HID bulb may flicker, change color and appear weak. Generally, if flickering is happening with OEM equipment then the problem is the ballast or the igniter. Not the bulb. If you are upgrading to HID lights it is because there isn't enough power going to the ballast. In day running light mode, less power is delivered to the headlight. While at night full 35 watts are delivered to the headlight in which case the headlight works fine. Contact the manufacturer of your aftermarket HID kit for a solution.