w204 rear light cluster problem

[EmilysDad]

That really is p*** poor, especially on a brand that's considered to be premium/prestige

 

[Manjac]

I hope this helps other 180 owners, Two years ago I had my N/S tail light holder melt due to the earth fault, I tried to get it repaired under warranty but Mercs said NO. This week the O/S light went, this time i phoned Merc and got put through to Holland, told them my problem and Hey Presto, take it to your local Merc dealership and get it repaired under warranty FOC. Why could they not have done this years ago when the fault first appeared. They did in the US

 

[SuzieQ]

Resurrecting this thread for my old 2011 C class estate and maybe to help anyone else.
I noticed a problem with the lights about 2 weeks ago, initially it was the rear marker light. Looked at the bulb and nothing was amiss. Gradually over the next week I had a warning for every light in the offside rear light cluster. On checking the unit had burnt out with a wire hanging loose. I did a bit of googling and found all the US info about it being a recognised manufacturing fault. Persisted and eventually found someone who said VOSA in the UK had also confirmed it as an MB fault. So I emailed MB UK stating that DVSA (formerly VOSA) had recognised this fault in the rear light cluster and what would they suggest my next step is. 24 hours later their email said to book it into my local MB garage for them to look at it. I duly booked the diagnostic test at £130 and explained the issue and that MB UK had told me to book it in. Obvs not too happy about the £130 and when I dropped it in I spoke to the services guy, I said it didn't need the diagnostic because the problem can be seen with the naked eye- burnt out light cluster! He agreed! Happy to report they confirmed the manufacture fault and paid all costs, and I drove away within the day with the lights fixed and the car cleaned inside and out!

 

[EmilysDad]

..... Happy to report they confirmed the manufacture fault and paid all costs, and I drove away within the day with the lights fixed and the car cleaned inside and out!

Result. Well done for sticking to your guns

 

[deigo]

Rear lights acting silly

I've had A problem with my rear lights!
Please help as this is driving me mad
The front & mirror indicators flash as normal yet the instrument cluster flashes rapidly, when this happens the rear indicators don't work or reverse lights.
This also plays havoc with my headlight switch causing my front fog lights to go off, The fuel gauge also plays up at this point and the rear demister fails to work.

I checked the rear light clusters and the bulbs had started to melt at contact point because of overheating so I replaced all the bulbs and cleaned the contacts on the cluster. However the wiring and connectors seem to be in tact.
The bulbs get hot and the rear SAM unit located close to the drivers side rear light in the boot has several relays that are quite hot also.

The lights do work as normal for a short while when engine switched off for a while but then play up again at random.

My W204 has done some miles but that shouldn't be an issue

Any help will be appreciated thanks

im having exactly same problem.. did you manage to resolve the issue.. let me know asap plz !!

 

[coleyjf]

Had the same problem soldered a brown wire to negative section of rear light cluster and connected it directly to nearby earth (body of car) so bypassing faulty plug connection.Works fine next to no cost.

Thanks for this suggestion, I tried it last night and it solved the problem I was having with my rear N/S indicators, it also seems to make the rear lights brighter

It's an easy fix as after scraping the coating off a bit of the earth track on the custer it's easy to solder the wire and I just put an extra nut and washer on the bolt which holds the whole rear light cluster in place to secure the other end of the wire

You can see the over heating marks on the pin on the connector!!!! Definite fire risk

Cheers

 

[coleyjf]

Update to the above fault:

I've now driven about 400 miles after the fix (as above) to Ambleside and back and no more problems whereas I was having a Rear "Rear N/S indicator fail" every 10 or 20 miles previously

Thanks sid300sl

cheers

 

[coleyjf]

Update to the above fault:

I've now driven about 400 miles after the fix (as above) to Ambleside and back and no more problems whereas I was having a Rear "Rear N/S indicator fail" every 10 or 20 miles previously

Thanks sid300sl

cheers

UPDATE AGAIN!

Just had the same problem recurring!!! so decided to do some serious looking at it!

In the end I found that as well as the brown/earth wire being a bad connection causing it to heat up and oxidise causing bad connection, the insulation between the earth and the indicator wire (adjacent pin along the dreaded black connector) had also been breaking down when more than one light was on causing the lights to go into "faulty bulb" mode.

As a temporary solution, (prior to replacing the connector and light cluster as described previously) I "patched" the indicator "operate" wire from the cable loom, just before the connector, directly to the wire from the LED indicator cluster ommitting the light cluster completely for the indicator LED cluster.

I cut the N/S indicator "live" wire just before in enters the black connector (the adjacent pin to the brown earth wire) and soldered about 6 inches of wire to it and soldered the other end directly onto the "red" wire leading to the LED indicator cluster, rather than damaging the connector on this red wire I scraped a small length of insulation off just above the connector and soldered it there and then taped it up, so I can re-use the connector onto the new light cluster when I do the permanent repair

SO FAR ( touch wood) it seems OK ! I've also soldered a wire on the O/S cluster from the earth track to a good earth as a preventative measure .

Cheers

Jim

 

[EmilysDad]

You'd think that after 100 yrs + of making cars, Mercedes should be capable of making a light that works.

 

[Abzmercowner]

Looking for help not too sure if it is related to this but a similar failure
I have a c220 w204 2012 automatic
The left rear light cluster tail light isn't going on but turning on when the brake peddle is pressed as It should.
Strange fault as I thought it was a bulb so replaced the bulb and looked at the connector no signs of burning the brown wire is ok as well and the pin connectors make and female look fine.
It's working only when the brake light is pressed any advice or help would be appreciated.

 

[coleyjf]

Hi Abzmercowner

Sounds awfully like an earth fault to me? I'd be inclined to try connecting the earth track on the bulb assembly directly to a suitable earth point (one of the nuts that hold the unit in place would be suitable) .

Just to try it if you've got three hands ( a helper ) unclip the bulb holder assembly and hold a piece of wire, one end on the on the earth track ( just see where the end pin that the brown wire is connected to) , the other end on something like the boot catch and get someone to switch the lights on. If they now work, solder a wire from that track to a screw earth as described earlier in this thread.

Worth a try

Jim

 

[Dave Hughes]

Hi Abzmercowner

Sounds awfully like an earth fault to me? I'd be inclined to try connecting the earth track on the bulb assembly directly to a suitable earth point (one of the nuts that hold the unit in place would be suitable) .

Just to try it if you've got three hands ( a helper ) unclip the bulb holder assembly and hold a piece of wire, one end on the on the earth track ( just see where the end pin that the brown wire is connected to) , the other end on something like the boot catch and get someone to switch the lights on. If they now work, solder a wire from that track to a screw earth as described earlier in this thread.

Worth a try

Jim

Hi Jim
I need help I have a 2014 c class coupe and my rear passenger led indicator just won’t work but the bulb below it flashes like an indicator?
I have tried a better earth from the brown wire goin in to the block to the bolt on car nothing!
I have tried linking the wire next to the brown one to the top red one and still nothing it’s driving me mad any ideas
Thanks

 

[MyMerc]

Hi Jim
I need help I have a 2014 c class coupe and my rear passenger led indicator just won’t work but the bulb below it flashes like an indicator?
I have tried a better earth from the brown wire goin in to the block to the bolt on car nothing!
I have tried linking the wire next to the brown one to the top red one and still nothing it’s driving me mad any ideas
Thanks

Hi Jim I’m not sure when you posted this.
I have a very similar problem C220 2014
Intermittently when I indicate left a warning is displayed on the dashboard saying rear bulb fault ( fast flashing and reverts to brake light) I have been trying to sort this out since last Oct had bulbs changed, connecting leads and SAM unit. Still haa as e the problem. Can anyone help Thanks