Problem: Rear right side marker lamp

[aficionado]

Hi

I drive a W204.

One night, just after switch the engine on, a warning appeared on my instrument cluster:

'Rear right side marker lamp'

Then I went out to check and one of the rear lamp (upper right side) was not turned on. I thought maybe it's time to change the bulb. But then I gave it a little pat, and it turned on!!

This problem keeps on happening once in while, and it is annoying when the message appears.

Can anybody advise please?

 

[219]

Bad connection ?

Either in the lamp holder , or a plug in connector ?

 

[grumpyoldgit]

I used to get that on my Volvo Estate and used to do exactly the same thing, give it a tap and it would come on. Worked for several months and I endured it as it only happened occassionally. Anyway, it was the bulb failing, I pressume the filament was broken and making contact most of the time. Replaced the bulb in the end, fault fixed.
As has already been suggested though, check the bulb, bulb holder contacts and the earth.

 

[Ted]

Bulb.
Common 'fault' - when you hit the lamp with the light on, the filament vibrates, makes contact, and 'welds' itself to the support inside the bulb.
Tends to fall off again when the lights are turned off, but sometimes lasts a day or two.

 

[aficionado]

I've checked the connection. Opened up the compartment, pulled the wires from the socket and put them back. Couldn't see anything wrong with them actually

Thanks to grumpyoldgit and Ted. I am now feeling quite relief as I've known the source of the problem.

And Ted, very good yet simple explanation. Thanks