All right - THANK YOU for the excellent list of suggestions.

NEW QUESTION - on the starter, should the small wire show a connect to ground ?

I am really testing every single thing I can for resistance and the small wire on the starter
does go to ground, wire is still attached to starter. Suppose I should disconnect and check that.

Can tell you that with large wires disconnected from the starter I get a 3k ohm to ground with alternator plugged in, 100 percent resistance (no ground) when alternator unplugged. This is good.

I have been using the 300SD as a control group sort of, disconnecting and testing on that car as these two are virtually the same setup. Still not enough clear information
to blame anyone part or circuit.

Still have everything disconnected.

I may start hooking everything back up and just keep testing along the way.

__________________
80 300D 340K Owned 30 yrs
83 300SD 440K Owned 9 yrs - Daily Driver 150mi/day
02 Z71 Suburban 117,000
15 Toyota Prius 2600 miles
00 Harley Sportster 24k
09 Yamaha R6
03 Ninja 250