Sunday, January 2, 2011

Mercedes – Benz ML320 HID Xenon Conversion Kit Installation Guide

Dear Viewer,

I am posting my way of how I installed an aftermarket HID conversion kit on my 2002 ML320. I have surfed the web but for tutorials for this specific vehicle but could not find a site or blog showing how this was done. Feel free to read what I have done but know that there might be other ways. The kit consists of H7 bulbs and 35W ballasts. The temperature of the bulbs in the installation is at 8000K but if you want to have an OEM look, 5000K is your closest bet. I personally want some blue color but not too much. Please leave comments so that others may find this site useful too. Thanks you and good luck!

- Taras Levkiv

I purchased the HID kit and the relay kit on eBay:

After ordering the kit, I received it and opened up the package. This is what I got:

I unplugged the battery and removed both headlights. (Do not forget that you need to take off the plastic piece under the headlight to get to the other two screws!)

I completely unplugged the headlight from the car by removing the turning signal and headlight connectors. Then, I removed the weather protecting lid and took out the original halogen light bulb. (low beam).

Remove the metal fitting from the bulb socket that holds the bulb in the headlight because the Xenon bulb will not stay in place on its own. Then take the metal fitting and thread the wires connected to the new bulb of the HID kit through so that it gets to the bulb itself. (Make sure to take off the plastic cover the protects the bulb first and that the metal fitting is facing the correct way so that it can turn into its housing properly)

Notes: You will most likely have to bend the metal fitting to get some the wire harnesses through it but make sure not to change its shape too much.

Shape the metal socket back to its original form (or as closely to it as possible) and plug the Bulb into the headlight. It should be real tight with no movement (just like the factory halogen bulb). Take the socket where the original bulb would go and connect it to the kit making sure positive (+) meets positive (+) and vice versa. (This can be checked with an electrical meter if you do not know the color codes)

Notes: In the picture, my headlight is burned because one of my standard halogen light bulbs got too hot and burned inside L.

Now, to get the plastic weather protecting cover back on and still have the wires coming out, you will need to make a 1” inch hole by using a drill and a 1” drill bit. Drill the hole in the middle of the cover. Once this is done and you have sanded down the edges of the hole, thread the rest of the wires through and use the rubber seal on the kit to cover up the whole. This will keep the inside of the headlight still protected.

Snap the cover back on and the headlight should be ready. Repeat the same thing for the other headlight.

We are now ready to mount the ballasts to the car. I was looking for a place for a while and finally noticed an optimum hidden place that is far from other tubing and the engine itself so no drilling is necessary!

You will find a hole under the stud where the headlight is screwed on to hold its place. Use that hole to secure your ballast by using the bolts provided in the kit. (Make sure to zip tie your ballast to the mount provided before you mount it to the car so that it will not move or slip for sure). This is all you have to do to mount the ballast to the car!!! Do this for the opposite side as well.

(passenger side)

(Driver side)

Now that you have mounted the ballasts and prepared both headlights, it is time to connect the relay harness. Please purchase this at the same time because you WILL need it! If you do not, your lights will flicker like crazy when the car is turned on because there is not enough constant power given to the ballasts to light up the bulbs. The relay harness gives direct power to the ballast from the battery.

Obviously, unwind the relay kit and loosely place it where it is supposed to go. You can hide the wires later. Make sure that the short ballast connector on the relay kit goes to the ballast closer to the battery itself. The longer one will go to the opposite side. For this car, the battery is located on the passenger side.

Connect the positive (+) wire of the relay kit to the positive (+) side on the battery and the negative (-) with the negative (-) side. (Do not connect the battery plugs though).

Connect the Relay kit to both ballasts. (This will result in not using the big plug that comes out of the headlight from the Xenon bulb)

You have Successfully Connected the Relay kit and we are almost done!!!

All you have to do not is connect the black and red wires that come out from the bulb to the red and black wires that come out of the ballasts. They snap right on and have the weather protecting heads for optimum security and durability.

When installing the headlight back into its housing, make sure to move the wires to the sides of the headlight so that you do not pinch them when placing the headlight back in. You can zip tie them so that they are not scattered as well.

Plug back the whole headlight and the turn signal. Reconnect the battery to give power and test if the light bulbs light up. If they do not, remember that you have to make sure that the positive (+) and negative (-) wires in the socket where the original halogen light bulb was connected matches the positive (+) and negative (-) wires of the HID kit!!!

Now that the lights shine when the car is on and off, secure the headlights back into their housing and place the plastic cover pieces under the headlight.

You have now successfully transformed your old halogen lights into Xenon lights that shine brighter and last longer! Your drive will be safer at night and the visibility will be much greater. Remember to adjust your headlights so that the beam is no higher than the bumper of the car in front of you at about 20ft. distance.

Enjoy your new lights!!!

Again, leave comments if it was helpful or if you have any questions. Once again, I am no expert at this and just wanted to share my way of doing this because I have not found a site specifically for a ML320.




  1. Hey man thanks for the write up. Does your truck have day time running lights? also did you have to get anything programmed? let me know if you can,


  2. Hey there! No, I have no day time lights and I did not have to re-program anything. It was simply plug and play. This was my first project ever on the truck so I kind of did it on my own. It works pretty well. Sometimes I get a flicker then and there but rarely. I cannot figure out if it is from my wires being bent or if the relay harness is too tight, or simply from hitting big bumps and pot holes on the road. lol I've looked at all of the possibilities. Some people say I need a conversion kit but the relay seems to be working well. Maybe I still need the conversion kit. idk. Thanks for reading this though and hope some it helps or gives some ideas!

  3. Great installation glad-the diffrence is great. installed it on my chrysler sebring 07 pretty much simple plug and play and installing relay pretty simple

  4. Hey! Sweet installation guide. I've been looking for some Xenon/HID headlights to upgrade and replace the stock headlights that I currently have on my 2002 ML320. After reading your guide and watching the before and after videos, I think I'm considering these lights as an upgrade. Have you had any problems with them other than the occasional flickering?

  5. Also, does this kit include high beams within the lightning component?

  6. Hey there, thanks for the comment. I'm pretty sure they have high beams as well. However, the kit does not come with it. You can simply buy 2 of these because both high and low are 12W. Other than the occasional flicker, I have no problems with them.

  7. great man great ideas i like it for my car and love it like a fan so your work is appreciate able and in the last i would like to thank you dear for sharing it with us so nicely ebay hid lights

  8. hid lights nice blog to read and to get information for led so nice of you and keep it up

  9. Thanks for the informative post. Where can I find a Hyundai Elantra 2006 model of car bulbs and I prefer for a Xenon Bulbs.