George it is the exact same engine that I have that you helped me with ,were is a small board inside the tender and mine had the 8.4 volt battery. the board you had said was a distribution board. the guy said but some people don't listen that the battery inside the tender looked to him like it was JURY RIGGED, that why I was not sure what board he had in it. mine had a ps2 5 volt that was bad and his is the exact same ID number . maybe his battery is bad or weak or maybe it's the wrong battery?
What do You think George!
Alan
PS George also there is no jack under the tender to charge any battery with. I'm looking at mine right now.