Number plate lamp bulb

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Active Member
May 20, 2018
Spalding Lincs
2006 C220 Estate
2006 220cdi
I just had my warning come in for the left Number plate lamp not working. I had fitted led bulbs that are ok with the a CAN System So I ordered a new bulb, fitted it and apart from a flash it won’t work. The old bulb had failed as I tested on a battery.
Do these turn off the power until a correct bulb is fitted as I seem to remember with another bulb I had to turn the switch off and back on for it to work.
I will try a normal bulb but was just wondering.

My former car, a CL turned off the supply voltage if the system detected a faulty lamp. Replacing the lamp while the engine was running was not OK. Had to turn the ignition off and on in order to make the system perform a new try. (It was also often necessary to replace both L and R side from the same batch.)

I also tried LED-lamps. Several different brands "CAN-bus safe" etc. Experienced the same thing. Just a waste of money.

Finally I purchased blusih "old style" filament lamps. Almost white light, no error codes and the advantage of the dissipated power keeping the number plate sockets free from moisture and condensation.
Thank you
Thats along the lines I was thinking.
I will get the old type bulb and report back.
thank you
When testing the supply for a non-working taillamp, can a tester like the on in the pic be used? or because its part of the canbus system, is there a special tester needed?
Thanks in advance for your help.


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    Auto Face Tester.jpg
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Umm, why would you want bright number plate lamps?
After I fitted the correct normal Type bulb and turned everything off and back in all worked as it should.

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