In W124 circles the OVP (Over Voltage Protection Relay) is the Evildoer.

I just remembered the W210 has a K40 relay that when feeling ill presents as
all kinds of things that it's not.

SA @ RBM in Atlanta said it's possible to see this kind of Symptomology with a
flaky K40 (The Only way to tell for sure is to hook it up to the STAR machine
@$110.00 USD)(Do Techs not use Digital Multi-Meters ? Silly Me,Not when
the Almighty STAR diagnostic machine can clip your pocketbook/wallet for $110.00 !)
I have to be fair,it's probably $110.00 just to have a R.O. written no matter what.

BUT he agreed that the Voltage test of the Alternator would
tell you if it's the Alternator[and/or It's Voltage Regulator].

__________________
'84 300SD sold
124.128