Your correct that the internal ETA wiring is probably half dust with wires shorting to other wires!

But I wouldn't buy an Ebay used or rebuilt . . . have yours rebuilt. Just a suggestion :)

any recommendation for a reputable builder?

When my ETA died, I documented it here. Over the years, other MB owners have written to me and I've posted their results.

IMO, the best is Beckmann Industries but, unfortunately, they're the most expensive.

You might try S-Class Eddies here. He consistently has good, used and reasonably priced S-class parts.

Victor has helped a lot in this forum and his prices are reasonable for a re-wire of your ETA. Check it out here.

I took it to a local mercedes indie. The tech said its my ignition control module. The car was running on 4 cylinders! He did a compression test and it tested good. Everything led to the ignition module! He said the ASR light should turn off when the engine gets running on all 8. He commented the replaced parts did help alot.

Success!!!! My S500 is back to normal. No ASR or Check Engine light! Runs better then it did with the old wiring!!

You've got a new car complete w/ new modules. . . glad it's fixed. :)

Do NOT get an ETA from Ebay. Check first with Victor in Brooklyn or BBA Remanufacturing in the Boston Area. And be sure if you buy one, it is the exact same part number as your current unit.
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Anziani