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Discussion Starter #1
Hi there. I just bought a 1984 300D and noticed my dash lights were very dim. I ordered LED's to fix that problem but at the same time I noticed all the lights in the center (ie. climate control, etc.) were not working. I thought maybe it had something to do with the dimmer but I just took the instrument cluster out and noticed the dimmer had been jumped with a soldered wire. Which after research seems fine. I don't mind not having a dimmer.
My initial question is it the same fuse for the dash lights and the center lights? I figure I may as well check that first. But if it is the same fuse then I know it is not that because the dash lights did work, just very dim.
Thanks
 

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1989 W124 260E
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We are talking about fuse 1 in your fuse box .But i will tell you this - so many other items are used on this fuse you would also have found other item on your car that are not working . So not that i am afraid.
 

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1983 W123 200T
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Are you talking about the switches on the centre panel not being illuminated?

If so, these are lit via several fibre optic cables which conduct light from one bulb behind one of the centre panels. It's likely that the bulb has blown, hence all the switches not being lit.

If it is only one or two switches which are unlit, then it's likely that the fibre optic cable has become detached from that particular switch.

More info in this thread with photos...

 

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Discussion Starter #5
I looked at that link and am confused? I don't see the spider/octopus leg??This is what my bulbs look like behind CCU? Am I missing something?
 

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1983 W123 200T
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May be more info here..


 

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Discussion Starter #7
Update: I just put in the LED's and all the dash lights look great. Still dark on all the console lights (ie. spider and CCU)??? Can anyone tell me where or how to trouble shoot this? Thanks
 

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1983 240D 4-speed
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You are going to need to replace those little light bulbs. I know on the cars with the Auto Climate Control you can easily reach both the CC lights and the light from the switches. Video is available here.

Not to hijack, but can someone tell me where exactly the "spider" is on a manual climate control 240D? I see in that thread linked above that the OP managed to bring his "spider" outside of the dash. I thought it was mounted behind the heater box, which is riveted in, so I deemed the inop switch lights to be too much work. But after looking at that thread it seems I just need to look harder...can anyone help? I know its just one light bulb and would be very happy to finally get some more light in the interior.
 

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Discussion Starter #9
I pulled a few out and they seem to be good? I tested a few and they worked. If 1 is out, will the whole string be out?
 

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Discussion Starter #10
Hi all. As of now I have the center console all apart and none of the lights connected to the brown and blue wires are working? To be honest I am at a loss as to my next steps to troubleshoot the wires? Can anyone help me out on that? Thanks
 

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Discussion Starter #12
Thanks for the diagram. Apparently I am not very electrically savvy because its hard for me to make heads or tails of it. LOL!
I did physically try and trace the brown and blue wires that all the bulbs are attached to the best I could. It seems that the blue wire went to a mini cluster of two more blue wires and were screwed into the body as a ground?? Which I thought was odd? Shouldn't the brown wire be the ground? And I traced the brown as far as I could which went up and back into all sorts of wires seemingly to the back of dash??? I couldn't really tell after a certain point.
Anyway, I was wondering if I could just bypass that brown wire and take a wire and connect it from one of the lights on the dash that I know has power when the lights are turned on and splice it into the brown wire down near the center lights to give the center lights power?
 

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1983 W123 200T
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Do you have a multimeter to check power to the wires and continuity?
I'll have a look at the wiring diagram later and see if I can see where the lights get there power.
What you suggest should work though. Maybe add an online fuse too?
 

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Discussion Starter #14
I do have a multimeter not that I am at all confident in my abilities to use it. But I can do whatever is suggested. Thanks I will wait to hear your thoughts about the wiring. I appreciate it.
 

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1983 W123 200T
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You should be ok without really as the wiring is post fusebox.
There's lots of sites that explain how to use a multimeter to check continuity and power better than I can.
 

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Discussion Starter #17
I used a multimeter and have continuity from the ground, blue wire @ bulbs going into CCU, to brown wire cluster behind instrument cluster. I also have continuity from the brown wire @ bulbs into CCU, to the 15 pin plug that plugs into the instrument cluster. I don't know if this means anything but I am showing continuity from that brown wire (bulbs @ CCU) into 3,4,7-12 holes in that 15 pin connector? Should that wire have continuity into so many wires on that plug?
 
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