3rd brake light warning but working

[gh3382]

ON my 2010 ML W164 I have been getting intermittant warnings messages regarding 3rd brake light but when I check it the light is working as it should .

I am tempted to check the rear SAM for any water ingress.

Any suggestions as to cure this or confirmation that I should check the SAM appreciated.

GH3382

 

[Blobcat]

I’d take the connector apart, apply some contact cleaning lubricant and put it back together

 

[grahamcol]

I had the intermittent 3rd brake light warning on my 209 series CLK. It gradually became more frequent until eventually it was constant. At this point the led strip wasn't working at all. I replaced the whole unit and it has been fine ever since.

 

[mioba]

Could be weak solder in the strip somewhere causing error. Dont chase things that are not relevant. I bet if you replace the strip it will be fine. As mentioned, first port is certainly the contacts

 

[gh3382]

Thanks for the replies . I will have a go at the contacts this afternoon.

GH3382

 

[gh3382]

UPDATE

I replaced the light. Bit of a bind to get out but there are utube videos on it.

Cost was £83 inc VAT and P&P off fleebay from a Mercedes dealer who had quoted me £97 + vat on the phone.

When taken out all the interior of tailgate frame was wet so I dried it out with a hair dryer .

When I fitted the light I put a thick bead of silicone around the light opening in the tailgate cleaning off any surplus with a wet rag whilst still wet.

I am pretty sure using a jet wash has foorced water into the light so hopefull a good silicone seal will stop that.

Thanks for the help given.

GH3382.

 

[mioba]

Silicone is not recomened. It gives of acid which iant good for paintwork. It wont withstand temp of Summer - winter and will probably be worse than the gasket

Is there not a rubber gasket on them. Not like them to leak.

If you must a sealant then something like tiger seal / Sika flex.

Glad your light is all working now!

 

[ajlsl600]

If using a flexible sealant like sila flex. I take up all the slack with fixings, clear up the mess then tighten 4,5 hrs later when it's near or gone off.