Just saw that you had generator work done. Guess old age is setting in! Had a motor shop recently rework a generator and it was blowing the OL, sparks flying off etc. Turned out the motor shop installed the brush riggings facing opposite of what they should be. One of those things I kept staring at by comparing it to the car next to it and sure enough---backwards. Swapped them around and it ran perfectly. Never trust anyone!