I have a 1982 300sd, The headlights keep burning out, I took it to the shop they said that I should replace the battery and the alternator. After doing that it worked for about a week then the lights burned out. Has anyone seen this type of problem? This problem is with both head lights high and low beam. I have checked the four related fuses. They are fine.

At this time I am thinking that it has to be something common to the all the headlights. Is there an overvoltage relay that protects the headlights?

Running sylvania H6054, sometimes the feliments are shartered. When they go out, they get brighter and then dimmer then they burn out.