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.

Check your relays and fuses....

You may have an electrical sort.... Inspect the wire harnesses and plugs that connect to the lights

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2006 BMW M5 "Heidi" @ 109,000 miles
2005 MBZ C55 AMG "Lorelai" @ 165,000 miles
1991 MBZ 300E "Benzachino II" @ 165,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles

(On the hunt for a good used M103 engine as of 6/10/23, PM me if you have one to sell!)

Over the years, in various cars, incuding, but not limited to MBs, I've had a few headlights "pop" from bad voltage regulators. See what voltage you're putting out at >2000 rpm.

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

I checked the voltage at 2000 rpm and it was at 14.37 volts.

Checked the for fuses they check out ok. Checked the power at the headlight plug, and it was at 12 volts.