Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thank you for the question. If the bulb has been replaced then more than likely the issue is in the ballast. These fail frequently. The voltage to the headlamp should be checked first just to be sure that there is not an electrical issue. If there is power there then it is the ballast. It can typically be replaced without having anything reset by the dealer. If you need more help please let me know.