Lights won't work
Thread Starter
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Joined: Oct 2016
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E320
Lights won't work
2000 E320 wagon; I'm not sure what the lights below the high beams are called but mine are not working. Bulbs are good. 12 volts coming out of the socket. Sockets are good. Perplexing. Is there an amperage requirement for these lights to work?
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Joined: Jan 2004
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From: Seattle WA
99 E320
if you've verified that the bulb filament is intact and lights up via independent power source,
and you've verified that 12vdc exists at the bulb socket when the light switch is deployed,
then the only thing I can think of is that it is experiencing power interruptus between the
socket and the bulb so clean the bulb contacts AND the bulb socket contacts.
then, plug the bulb into the socket, turn on the power, and take another voltage reading
because I'm presuming you did the aforementioned verifications separately.
it may be something bigger, as the odds of both bulbs being out at the same time is low
unless the cause is from something further upstream. It's a very simple circuit so you'll
just need to be systematic with troubleshooting.
also, it would help if you are specific with your descriptions and to detail how you've
arrived at the fact that the 'bulbs are good.' also, why did you only test one socket
instead of both for voltage?
and you've verified that 12vdc exists at the bulb socket when the light switch is deployed,
then the only thing I can think of is that it is experiencing power interruptus between the
socket and the bulb so clean the bulb contacts AND the bulb socket contacts.
then, plug the bulb into the socket, turn on the power, and take another voltage reading
because I'm presuming you did the aforementioned verifications separately.
it may be something bigger, as the odds of both bulbs being out at the same time is low
unless the cause is from something further upstream. It's a very simple circuit so you'll
just need to be systematic with troubleshooting.
also, it would help if you are specific with your descriptions and to detail how you've
arrived at the fact that the 'bulbs are good.' also, why did you only test one socket
instead of both for voltage?
MBWorld Fanatic!
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Posts: 6,130
Likes: 1,117
A gaggle of MB's
Are you saying both original bulbs "died" at the same time ?
Are you saying - one originals dies first - and when you went to replace both at same time (which is smart) - the replacements don't work ?
If you have replaced the original bulbs with "new" bulbs - there are two metal stubby alignment pins on the base of the bulb to guide into the socket - check the "pin" alignment on of a original bulb - and the alignment of the pins on the replacement.
Bulbs can be same/correct Bulb# - if I remember correclty late tonight - I believe Mercedes (and Audi - maybe even VW) use a 12PM/4:30-5PM pin alignment - and US/Japan (much more comment) with same bulb use a 12PM/6PM alignment - I "think" - jamming in the US/Japan 12PM/6PM into the 12PM/4:30-5PM socket can cracked the socket/and-or lead to non-working.
Hope this helps - again it's from my late-night head..
Are you saying - one originals dies first - and when you went to replace both at same time (which is smart) - the replacements don't work ?
If you have replaced the original bulbs with "new" bulbs - there are two metal stubby alignment pins on the base of the bulb to guide into the socket - check the "pin" alignment on of a original bulb - and the alignment of the pins on the replacement.
Bulbs can be same/correct Bulb# - if I remember correclty late tonight - I believe Mercedes (and Audi - maybe even VW) use a 12PM/4:30-5PM pin alignment - and US/Japan (much more comment) with same bulb use a 12PM/6PM alignment - I "think" - jamming in the US/Japan 12PM/6PM into the 12PM/4:30-5PM socket can cracked the socket/and-or lead to non-working.
Hope this helps - again it's from my late-night head..
Thread Starter
Newbie
Joined: Oct 2016
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E320
I did a number of tests to determine what the issue was and came to the conclusion that there is an ampere requirement. I checked out a junkyard car and found a resistor along the wiring going to the bulb. Why it's there, I don't know. I liked the response about the daytime lights. Thanks everyone for their input. I've decided that my car doesn't like me and like a dog that gets shuffled to a new owner will rebel and be non-cooperative. More issues to come.
