SPTT,
Write it 10,000 times on your driveway.
All the other issues: Different Battery(s) on Different Chassis [of different ages?]
(With who knows WTF for Service History or Climactic Conditions Endured ???)
(Of who knows how many miles?)
Are you seriously expecting anyone to sort through your "ShotGun" of Questions
Sanely???
Hey, Brotha we try our best,but nobody here claims to be Omniscient.
The FSM has a step by step set of procedures used to diagnose and repair
problems.
'Go outside the procedures and you're taking your chances on a sucessful
repair.
"Guessing" or "Throwing Parts At" are not part of any repair procedure.
[Except @ Stealerships,where they're "Guessing" with your Money...Until your
Lawyer gets through with them.]
Here's the Scoop:
http://w124-zone.com/downloads/MB%20CD/W124/Main.html
Everything you need to know is there.
(Or on the SEARCH button marked ADVANCE)