Brought the trooper to Pipton's shop. The IC regulator of the Hitachi alternator was shot, as i feared. They didn't have the part but, upon checking their sources, would be able to source the IC+diode+stator for P16.5k(from isuzu i think). They had a surplus nissan 90A unit with the same bracket and connectors as the trooper's for P4.5k, so this was what i opted for. Hope it lasts.