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Discussion Starter #1 (Edited)
Hi there guys. Fighting here with the "no dash lights" problem. Here's the doubt. Power for the cluster comes from fuse 3, to the headlight switch, and then, to the cluster. But where does it input the cluster to power up the rheostat? Thanks and cheers from Brazil.
 

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2014 G550, 2000 SL500, 1995 E320 Cabriolet, 1980 TR8
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The following answer is based on a US cars, so your may be different, but I hope this helps.

Power from the head light switch comes in on pin 13 of the X3 connector on the back of the instrument cluster, however it may be possible to diagnose the issue without pulling the cluster first.

Exactly which "dash lights" are not working? The system is in three parts:

Part one is after the head light switch and before the rheostat and the red fuse. If your factory radio back light and/or ash tray light works, you have power here​
Part two is after the rheostat and the red fuse but before the interior illumination amplifier and includes the instrument illumination bulbs and some of the other interior back lights. lf you have power to part one of the system but nothing else, suspect the rheostat and/or the red fuse.​
Part three is the interior back lights driven by the illumination amplifier. If you only have some of your interior light not working (but the instrument ones do), suspect the amplifier or fuse 9.​
 

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Perfect Floobydust! I've just found out what happened. I had absolutely no lights (dash nor interior). But, some considerations. The N40 amplifier was working just fine (tested it), but wasn't receiving 12v on the 58d pin. The red fuse was pristine, as it was the rheostat. The headlight switch was tested, and worked good as well. Testing continuity, I've found out that one of the tracks on the circuit was burned out, preventing voltage to exit the cluster and reach the terminal block X6, and consequently the 58d pin (that feeds the 58D - X6/1) on the N40. That said, I've soldered the broken track in order to reconnect it and just got back from the car. All works fine now!! Once again, thank you for your time and perfect explanation!
 

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2014 G550, 2000 SL500, 1995 E320 Cabriolet, 1980 TR8
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I'm glad you found the issue! It is interesting - this is not the first time of have heard of that trace burning out. One would think that the NLA red fuse is there to protect it. The trace must be too thin for the current load.
 
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I'm glad you found the issue! It is interesting - this is not the first time of have heard of that trace burning out. One would think that the NLA red fuse is there to protect it. The trace must be too thin for the current load.
Right! I've figured out that the trace that burned out was the one that routs to pin nº 13, and the problem prevented the voltage to travel and feed the lights. That's why I had nothing. Interesting what you've said about the red fuse. Should be there to protect, but it's not. Check it out.

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