Must of took some diagnostics to figure all that out.
If the harness is bad, it has to be replaced. If it is one of the ones that go bad (and it fits the year) replace it at the first sign.
It would be my contention that if one is having any of the effects of the harness problem it would be impossible to evaluate any of the components at the ends of the wires. The harness problem is really bad when it exists.
After that I would replace the OVP if it has a 5 as the fourth to last diget of the part number (I can't remember the whole number but the new OVP has a 6 and the old a 5).
Bosch Master, ASE Master, L1
33 years MB technician