So i noticed that my driver side head light was not working. My initial though was that it burned out so i replaced with a working headlight. It still did not work. i took the headlight off and using my multimeter checked to see if there is any juice. it turns out that there is 11.7v at the headlight jack. I also checked the passanger side and it was 12.5v, and the headlight worked on the passanger side. I took a harness of another car that worked fine and i still get 11.7v at the headlight and it wont turn on. the high beam works just fine tho. The only difference between the passanger and driver side is that there is a slight voltage drop. This does not make any sense to me. 11.7v should power the headlight just fine. I am not sure what the problem is. Any ideas. I am baffled right now.

Check your grounds.

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I LOVE CATS....AND FRIES

1981 300sd
1983 300sd
1985 300d
1983 300cd
1991 350sdl

I always start with checking the ground with electrical issues.

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You have 11.7 WITH NO LOAD; you are measuring the Open Circuit Voltage (OCV), which is nearly useless as a troubleshooting device. Check it with the light connected and you'll have ~0. You have a fuse, switch, or + wiring problem.

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James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

Mine did the same thing. I replaced the fuse with a brass one, and that solved the problem.