The Kelley II has eight alternators feeding 2 very large battery banks. As an alternator to alternator issue, multiples cause no issues. That particular MoPar ECU looks for disparities between alternator field current, and battery voltage.
GOOGLE MoPar ECU diagnostic codes for that vehicle. Codes are made available via a coded series of blinks of the Check Engine Light. No meter needed. The diagnostic codes list any and all parameters between battery and regulator that would cause a fault to be issued by the ECU. You don't need to enable the codes, merely read the list of faults and their particulars. Avoid the fault and you are home free. it costs zero to access this fault code information.
After posting this I will attempt online to access relevant ND regulator-plug wiring diagrams. It will show which wire to act as an on-off switch and another that is used as a sense lead. Hope diagrams are available.
