A couple of reasons. We are people with lives. Sometimes we don't' have time to answer. That's just the way the forum is. Second, electrical problems can be finiky (SP). so it may be difficult to determine. I know your post was detailed but sometimes it takes some brain racking to figure out. I was going to post that it sounds like a grounding problem. But you discovered it already. Glad you did.
Give us another try if you have problems. Sometimes were all very busy and living our lives.

Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car