Frank winn

I’m having the same issues however mine started when I left my one scan tool connected overnight and found a discharged battery the next morning. Used a jump box to get moving and have had charging issues ever since. Bought new alternator and battery. Inadvertently I left battery connected when I replaced alternator and shorted the hot side of the alternator while disconnecting, then replaced battery, had to replace fuse block on top of battery, continued to have under charging issues. Had to always have home battery charger connected while at home . One day I discharged battery (third or fourth time while driving) completely replaced battery and now system is over charging. I believe there is a second voltage regulator in ecm. Because the alternator has been bench tested several times at o’reillys and charges within parameters.