Chris wrote:
I am running the expensive B&C regulators on both systems with
the stock alternators with the internal regulators disabled.  
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The question that flashes into my mind is "how did you disable the internal
regulator?"
Opening the internal connection from the output that normally powers the
regulator does not keep the regulator from operating.  I'm just wondering if
there is some issue with your external regulator maybe providing the field
current to the internal regulator.  Perhaps worth re-evaluating that setup.

Al