I need some clarification about voltage regulators

[Lee]

Hey...thanks for taking a look. I'll try to keep this short.

I have a charging problem. "78 911 SC 3.0 Parish-Rhone alternator, with a Marchel regulator.

Generator light stays on after start...constant brightness at any rpm.

I have continuity along the d+/61 wire to the 11 pin connector, with a .3 volt drop. Between the connector and the regulator, I have continuity with no discernable drop. SAme between the connector and the alternator.

My grounds are all good, all have continuity. Ground between alternator and regulator shows .3 ohms resistance, and has continuity.

No discernable voltage drop between battery and alternator on the big red wire from the starter.

DF wire shows .1 ohms resistance, and has continuity.

I can't find any shorts in the entire electrical system.

My alternator, including the diode trio, has been checked three times, and is good. New brushes.

I get a flat dc volt reading on the df connector at the regulator when the engine is running.

Okay, my voltage regulator has to be the culprit, right? But I've tried two different regulators, a bosch and a borg-warner, with little effect. The Borg warner may have worked for a minute.

Is the paris rhone not compatible with bosch or borg warner? What shall I try next?

Any help is appreciated, as my car has been down since early November, and I'm starting to get kind of blue about it.