Sorry to drag this old thread up, but I recently worked on mine and I can answer a few questions posed in this thread. Perhaps someone will find it useful.

After pulling mine out, I discovered a few things. First is several cracked solder joints. Repairing that was no big deal. But then I noticed a burned circuit trace, and sure enough one of the resistors is getting very hot. By the way, that's what those metal plates are. They're resistors. What they do in this circuit is pretty cool. They are used as shunts to allow a circuit to measure how much current is being drawn by the lamps, thus allowing a decision to be made by logic circuits as to weather or not a bulb is blown. Their resistance is going to be extremely low, as they are metal and thick. Their wattage is high as they are carrying a bunch of current.

So, their resistance is very critical. Unfortunately, one of mine is on the way to burning up. It's darkened and shows evidence of having been quite hot. It totally burned up the board trace on one end and I had to do surgery. Basically, I had to peel back the bad trace a bit, cut off the burned portion. Then I had to scrape off the insulation varnish and expose some clean copper to solder. I then jumped a piece of 14GA stranded copper wire from my new trace pad to the base of the resistor.

Now, I'm wishfully hoping that the problem was in fact that the resistor got so hot that it unsoldered itself from the board slightly, which then caused the resistance to go up and up until the trace burned and the resistor started to deform. I'm really hoping that making a good solid connection to this resistor will alleviate its overheating. The 14GA copper will serve as a heat sink at the resistor base, so it shouldn't desolder itself again unless it gets really hot. Hopefully it will run cooler now..... Hopefully.


If the material was known, one could make a new one by stenciling the old one's pattern and cutting very carefully. You would have to match the material and the thickness exactly.

I wonder if the turn signals work at all without this module..... Hmmmm......


Merry Christmas


-tp

I don't believe any of the exterior lamps will work without this module in place.

__________________
'94 E320 with 272,000 miles. '92 500SEL 133,000 miles.
Mods to the '94: TomTom GPS in place of ash tray, Auto Dimming Mirror ,Memory seat, DEI 545T Auto lamps, DEI 530T Auto Up/Down Windows, DEI Remote Start, Motorola Bluetooth® Car Kit, Built in phone charger using factory phone wiring, RainTracker Rain sensing wiper, Keyless Entry, Ambient lighting of center storage compartment. Soon: factory heated seats, REST
Mercedes-Benz is my addiction of choice.
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