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My 2003 W220 has an intermittent turn signal problem. The driver side rear signal goes out from time to time. I have replaced the bulb and exchanged the socket from the other side and it still does not work. It will then suddenly start working for a day or so, then stop. When it is inoperable, the hazard light on the rear driver side does not work either. Any Ideas????
 

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Could be early signs of a failing signal switch. All control for the signals and hazards go through the signal switch in the steering column. If you are a do it do-it-yourselfer, when you have the problem present, get a digital voltmeter and check for 12 VDC at the + wire of the socket with the signal on. if you have flash voltage (surges of 12 volts and then drops back toward 0 volts... repeats), your problem is in the socket. If not you can get a wire diagram and check output voltage from the signal switch.

I would recommend get help though... Sorry for the possible bad news.
 

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Probably not... There is typically one signal relay. If that was the problem neither side would work. My 2000 S500 has a relay for the rear, both sides and a relay for the front, both sides.
 

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My 2003 W220 has an intermittent turn signal problem. The driver side rear signal goes out from time to time. I have replaced the bulb and exchanged the socket from the other side and it still does not work. It will then suddenly start working for a day or so, then stop. When it is inoperable, the hazard light on the rear driver side does not work either. Any Ideas????
Did you find the answer to this issue? I have the same problem.
 

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Check the harness wiring that goes up and down with the trunk lid, usually over time the wires rub together enough to tear away some insulation and cause all funny kinds of issues back there. You will need to remove all of the trunk paneling to get to the the harness.
 

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Its also worth checking the bulb holder. Sometimes it has insufficient contact on the 3 metal points or in my case, mild corrosion causing the error.

 

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Oxidation

Had the same issue on the drivers side rear signal. I noted that the bulb is difficult to remove/reinsert. I changed the bulb with the passenger side, and the problem remained on the same side. I got it to work intermittently. :confused:

My mechanic played with it, and he scraped off some oxidation on the circuit board. So far, so good, but he mentioned that he has seen it before on W220s and that the circuit board might need replacement in the future.
 

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I had the exact same problem and fixed it

A few months ago, my 2004 W220 S430 rear driver side turn signal failed. I thought the bulb was burned but it wasn't. I measured the bulb with an ohmmeter and it has a very low resistance (like 2-3 Ohms). I then put it back in the socket but not inserting the socket back in the tail light assembly, I was still measuring the same low resistance across the 2 contact tabs. But when I placed the socket with light bulb back into the light assembly, I was getting an open circuit right on the metal plate where the 2 tabs are. Then I realized the 2 tabs are not making good contact with the light assembly metal plate. Bent the socket tabs further up and scratch the contact areas with a little knife. Spray a tiny dab of WD-40 to prevent future corrosion. I then reassembled the socket back into the tail light and it has been working ever since.
 

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Similar problem with my right rear signal. When you mention "circuit board" are you referring to a small board, the size of a quarter, above the light assembly. If so do you know the part #?
 

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Hi,

My guess is posts 10 and 11 are spot on, most likely the "Circuit Board" contacts, which from memory I beleive is part of the Rear Light Cluster.

Failing that the Rear Sam / Fusebox could be giving issues due to water / damp ingress :wink

HTH,

Cheers Dave
 

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I agree, I did have problem with corroded contacts, cleaning with sandpaper did it good.
But do not ignore post #7 of last year. That sheaf of wires is pulled and bent with every opening/closing of the trunk lid, and the wear may lead to broken/half broken line.
The result is intermittent off/on.
A simple trick may point to the culprit, check the light when the lid is in the upright position, then push it down slow as if to close and watch if there is a change at the light.
Repeat a couple of times, if it reacts you found the source of trouble. The fix is gonna be a pain in the....
 

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Do not ignore post #7 of last year. That sheaf of wires is pulled and bent with every opening/closing of the trunk lid, and the wear may lead to broken/half broken line.
The result is intermittent off/on.
Hi,

So are you saying that the Trunk Lid Harness which carries wiring specifically for the Rear Number Plate Lamps and Central Locking and Soft Close Status Switches will somehow affect the Indicators ???

:confused:

I can understand it affecting the Trunk Lighting, as this is switched by Rear SAM, as a result of Signals from the Trunk Lock Switches, and also understand the effects it will have on Number Plate Lights, C/L and Soft Close ........
Still :confused:

Regards Dave
 

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Dave,
you are absolutely right. Sorry for my stupid mistake, the lid harness does not feed the tail light assemblies.
What I wrote is only relevant to connections on the lid.
Thanks for the correction.
George
 

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Hi,

Actually, I wasn't trying to correct you :wink

I was curious to know if you had experienced "first hand" a Trunk Harness problem that had affected the Indicators because I have seen some very weird and strange things that don't make sense happen with all Mercedes Electrics :laugh

Anyway, thanks for the clarification,

Cheers Dave
 

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Corroded Turn Signal Contact Areas

Its also worth checking the bulb holder. Sometimes it has insufficient contact on the 3 metal points or in my case, mild corrosion causing the error.

Agree 100%.
My left turn indicator has been clicking at double frequency for months now and driving me nuts.
I first tried swapping globes from the good side to the bad side but no luck.
I then replaced the globes and even pulled the External Mirror apart but no luck.
Today I decided to do a thorough analysis. Took me all day but it was worth it. No cost (other than the new globes which I didn't need) and no more double clicking.
It was the slightest corrosion on the contact areas on the bulb holders.
Here are some pics and how I fixed it.https://w220.ee/WIS_82.25_Signalling_Equipment/Emergency_Alarm_System
Regards,
Brian
 

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I took my 02 S430 to a dealer to get this same issue dealt with (12/16). Driver side was spewing codes, along with a host of other issues. The tech told me this is a known issue in that the production of the tail light assembly was done with inferior grade materials. The metal corrodes and leads to failed tail lights. The only known fix is to replace the originals with aftermarket parts which have a higher quality standard than the early non LED stuff.
 

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I took my 02 S430 to a dealer to get this same issue dealt with (12/16). Driver side was spewing codes, along with a host of other issues. The tech told me this is a known issue in that the production of the tail light assembly was done with inferior grade materials. The metal corrodes and leads to failed tail lights. The only known fix is to replace the originals with aftermarket parts which have a higher quality standard than the early non LED stuff.
Or thoroughly clean up all connections and spray grease the metal tracks from one end to the other :wink

HTH

Cheers Dave
 
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