file:///C:/Users/musta/OneDrive/Documents/humvee/niehoff-alternators-troublshooting-TG17_uid252021123202.pdf
C.E. Niehoff & Co.
N1225 / N1237 / N1505 Alternators
Troubleshooting Guide
Tang… You posted a link to a file on your personal computer that cannot be opened by anyone but you.
Tang8u Was trying to send you the file from Neihoff regarding alternator and regulator checks. Before before you go through that checklist, I would pull up every one of the rubber grommets and make sure that every connection is tight. I have seen them come free, including on my rig. Check and clean all battery connections too (you implied you did that).
Also, unlikely but still ensure both PCB/EESS plugs are on tight.
[EDIT- RWH’s post directly below mine is probably the best diagnosis. Failed regulator]