I had an accumulation of problems with my 190DT dash and I finally pulled it and fixed every problem I could find. Several of these problems are common complaints on this list and in the Mercedes world in general, and I'm sure a lot of disappointment has come from trying to fix them. So I'll document a few of the things I did. I'll post them here one by one.

First problem: one of my dash lights went out. New bulb didn't fix. Turned out to be a bad trace, which I bridged with solder. In the photo, the bridge is identified.

One of the Bosch wierdities is the "relay" in the center of the light panel. It threw me when I first saw it, because I couldn't figure out what a relay was doing here. Turns out, it's not what it looks like. If you follow the circuit traces, you'll see that it connects to both turn signal indicators through the two diodes. The actual turn signal flasher in this car is located in the electrical center, and I think it's solid state. This is a dummy relay which is just there to make the clicking noise when the signal is on. So Bosch saved having a primitive flasher somewhere behind the dash, and instead has a convoluted solid state system with a non-replaceable relay, just to make a clicking sound.

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My fuel gauge swung erratically. I've replaced the sender, checked all the wiring, and still the needle would occasionally swing madly. As it turned out, the gauges have wirewound inductors which are likely there to damp needle movement. The inductors are wound on plastic spools. The spool for the fuel gauge inductor had broken away, leaving the coil loose in the wind. When it grounded against the case, the needle would swing wildly. I'm going to have to salvage a gauge from a spare pod. But temporarily, I controlled it by applying a bit of electrical tape to the gauge case.

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I had a problem with my trip odometer. When I tried to reset it a few days ago, it became stuck. The regular odometer worked well, but not the trip. It turned out that the reset lever pivots on a steel pin that's pressed into the plastic. The pin had worked it's way out. I just pressed it back in, and it's ok for now. i don't have a good photo, I'll take a picture of one of my scrap parts if there's interest.

Finally, getting the dash in and out hasn't gotten any easier through the years. I can go through the dash vent or from below, either way I end up thoroughly lacerated. How did they ever install the dash pods at the factory?

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Those are just little scrapes ~ I get ones that bleed for a day or so....

THANK YOU for these tips ! .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better