Ample Power 120A Alternator

[Briggers]

Hi, I have a 1997 Hunter 430 fitted with an Ample Power 120A Alternator. There are four possible connections; the two main Pos’ and Neg’ posts, and a plug in lead with blue and white cables coming out.
Do you know if this is a Pos’ or Neg’ field control alternator? I’m guessing, since it’s an American alternator it’s likely to be positive field control. In this case it’s also likely the Blue wire is the field control wire, am I correct?
If so, what is the white cable for?
The reason I am asking is that over the years the wiring has been bodged and it’s hopeless to trying to sort it all out. I am replacing the Interchange Smart Regulator as it it’s broken with a Sterling Power Smart Regulator via a Sterling Power 120A ProSwitch R. Finding the correct field control wire is critical.
Thanks for your help..

[smac999]

Balmar uses blue field and white stator (tach). So it would be a good guess.

[GordMay]

FWIW: The “Ample Power Primer” includes wiring diagrams.
➥ file:///C:/Users/gorda/AppData/Local/Temp/ample_power_primer.pdf