I recently acquired my cousin's 2000 C280. The driver side turning signal's blinking speed recently became very fast compare to the normal steady slow blinking speed. I checked to make sure all the bulbs are working and they are fine. Anyone have a suggestion? Thanks very much in advance.

 

You sure the turn signals aren't maybe LED replacements as opposed to incandescent?

Ask your cousin if he changed his turn signal lights.

Or, maybe you just have a bad blinker relay...?

 

Thanks, yeah I checked that too and it's the incandescent bulbs. How do I check the relay (if that can be done)?

 

You may have a socket that is going bad. The tailights are known for this but check them all. Sometimes a nice coating of electric grease helps. Other times, I have just have a flakey bulb.