[2002c230]

My driver side turn signal on the headlamp went out today, and upon removing the bulb socket I noticed one of the electrical contacts was severely corroded. Cleaning the corroded contact on the socket, and replacing the bulb did not fix the issue. I checked the service DVD, and there is a DTB out for this issue. Says to do the wiring harness upgrade. However, it gives no information on how to clean the contacts within the housing. I'm sure just cleaning the contacts would solve the problem short term... I see no way of getting access to the area with visibility unless you remove the entire headlamp assembly. Have any of you had any success cleaning the contacts without removing the assembly? Also, has anyone done a DIY repair job on the harness?

 

[2002c230]

I guess not too many people have this issue considering I didn't get any replies. Does anyone know if the wiring harness update eliminates the grounded electrical contact within the housing? I would assume since it's a grounding problem the corroded contact is the negative, or ground. From what I could tell the negative is routed through bulb cover with the upgraded socket?

 

[2002c230]

Alright, just to clarify here... The upgraded socket eliminates both contacts within the headlamp housing. It costs a little over $40 dollars with tax directly through the dealership. I went back to the dealership after noticing there is a special tool used to un-pin the female wire contact from the wiring harness. The SLK 2.8 Blade, and Blade Holder will run you nearly $100 dollars! So, you're left with only two options, right? Either have the dealership install the upgraded socket for around $50-$100 dollars, or purchase the $100 dollar special tool, which will also have to be put on order. Takes a few days to get into the dealership...

Don't even think about asking the dealership to just remove the single wire real fast with their "special" tool, because the service department will just make you feel like a worthless idiot, and tell you they can't do that. I complained to the service manager about how I always get treated by these service jerks, and he said their attitude would be adjusted... He was even kind enough to recommend a shop that would remove the single wire connector real fast for free.

Of course the guy was backed up with work orders though, and I couldn't have him do that until Monday. Didn't feel like waiting, and being the type of guy I am it was decided to make a custom tool... Took about an hour of messing around to create something that worked perfectly. Plan on making a DIY thread when I get photographs, so I'll let you all know what I did later... I made the perfect set that replaced their $100 dollar tool for around $2 dollars.

 

[jackdash]

Having the same problem

Thanks for writing about this. I am having the same problem, but on the friver side headlamp left turn signal. I can see the corrosion. Swapped the two bulb holders and still had the problem. What exactly is the solution? Do you have to take the headlight unit out to fix this?

 

[Buellwinkle]

What does the pin look like, photos. I worked around electronics all my life and have pinned and unpinned connectors using crude tools like a paper clip. I know I can get pinning tools at any electronics store for a few bucks but even then, my paper clip has done it's job. Heck I unpinned the radio connector and pinned it into the correct ones for my Comand install so it looks like it came that way from the factory.

 

[2002c230]

No, you do not have to remove the headlamp. There is no easy way to fix the internal contacts after it has shorted out, and even if you do the problem will just continue Basically eats away the inside contact completely... You need to get the updated socket from a Mercedes-benz dealership.

Part number - 203 826 02 82 - $40 dollars

This is the socket that you remove which holds the turn signal bulb. However the updated socket has the wiring protruding through the socket out the backside. What you have to do is remove the turn signal wire from the headlamp wiring harness. Driver side turn signal wire is the black, and white wire.

The female contact within the harness has a spring setup that holds the contact in place. First you have to open the pin lock on the harness. Simply pry up on the side which has the small rectangle slot. Be carefull not to use too much force opening the pin lock. It's very easy to unlock... Here comes the interesting part. Now you have to un-pin the female contact. If you look at the contacts you will notice a small slot on the top, and bottom of each contact.

That is what the SLK 2.8 Blade is supposed to be used for. Very expensive tool for a little piece of plastic with two metal prongs... What I did instead was dremel one prong off of two 20 amp fuses. Use a 20 amp because it's the perfect thickness. Then dremel the remaining prong down to the correct width to fit within the slot. Worked perfect...

Anyways, when you get the female contact out the upgraded socket comes with a little plug. Plug the hole on the wiring harness that is left from removal of the wire. Simple insert the turn signal female contact into the new harness on the upgraded socket setup, and bolt the new ground cable to the ESP ground area. Zip tie the new harness to the thick set of cables sitting on the wheel well area, and you're done.

 

[angiebest]

Awesome thread! My car just pulled this little stunt Can I just ship the thing to you for a few weeks and you work all these little bugs out for me since you already know how to fix them all. haha just kidding. Anyways, thanks for posting this. I have no intention of getting to know the dealership any better and you guys are saving me from it.

 

[kuyagringo]

Good info 2002c230. Just had my driver side turn signal replaced by dealer for $125. Corroded contacts. Would have tried to replace it myself had I seen this thread earlier. I will try it on the passenger side, as I'm sure that will go eventually. Using this thread, and using the driver side updated socket as reference, it shouldn't be that bad. I'll let u know.

 

[2002c230]

Glad this thread is helping a few people out with the headlamp turn signal issues. If anyone needs help with this just ask, and I'll try to be more detailed. Even though my Mercedes is gone...

 

[angiebest]

My parts arrived today and I went out to change them, I already have the upgraded ones, must have been done before I bought it. Now I'm still stumped. Anyway, I just posted two on the for sale forum. My car would be there also if I wasn't so attached to it

 

[kuyagringo]

angiebest... willing to sell one of those upgraded sockets for $25? Let me know.

 

[2002c230]

Why don't you just return them for full purchase price?

 

[angiebest]

I live over an hour from the nearest dealer so I ordered them online, knowing it would be next week before I could go pick them up during business hours. Now I don't need them and they're not returnable. Oh well

 

[zeet]

Start a new thread, someone here will need them.

 

[Tri-Star]

I just bought a set on ebay yesterday. The dealership told me I needed upgraded harnesses but I have not checked out the harness yet just tried to clean the housing. Should arrive by next week.

The part number you specified is for all w203's correct?

 

[2002c230]

Yes, it is the same socket, and wiring harness setup for all w203's. Not sure if OEM HID headlamps are the same though when it comes to the turn signal.

 

[Tri-Star]

I have OEM Bi-Xenon. I'll have to get under the hood once the parts arrive. Thanks for the help again.

 

[Tri-Star]

Unlocking Pin Lock Question

I unplugged the headlight harness and see the wire that needs to be removed. I also identified the pin lock and you stated to be cautious and not use force to open the pin lock but i'm not sure if it is unlocked or not. I used a small flathead and placed it into the rectangular slot but do i need to remove the white plastic piece to view the contacts? Please help!

 

[2002c230]

Tri-Star, can you include the reply to this question that I sent as a private message? To answer something I left out. No the white piece is not removable, and doesn't need to be removed. Simple pull up on the pin lock slightly, and it will stay unlocked.

 

[KevinH2000]

This is a very helpful thread and I appreciate the work that the original poster did to help fellow W203 owners. I want of provide one hint that builds on the previous work. Specifically, the original poster had to create his own tool to un-pin the electrical connector as described here:

The female contact within the harness has a spring setup that holds the contact in place. First you have to open the pin lock on the harness. Simply pry up on the side which has the small rectangle slot. Be carefull not to use too much force opening the pin lock. It's very easy to unlock... Here comes the interesting part. Now you have to un-pin the female contact. If you look at the contacts you will notice a small slot on the top, and bottom of each contact.

That is what the SLK 2.8 Blade is supposed to be used for. Very expensive tool for a little piece of plastic with two metal prongs... What I did instead was dremel one prong off of two 20 amp fuses. Use a 20 amp because it's the perfect thickness. Then dremel the remaining prong down to the correct width to fit within the slot. Worked perfect...

There is a commonly available tool that you can use to unpin the contact from the connector. I've had this one for several years and I think I paid about $10 for it. It has come in handy on several projects.

I used the prongs at the 12-o'clock position to un-pin the connector.

Here's a photo of the tool inserted into the connector.

I bought a set of used bi-xenon headlights and the seller had cut of the wiring harnesses. I had a set of connectors to practice with before tackling the job in the car.