[quote=&quot;wmthrower&quot;:cebdqld5]The culprit was a bad connetion in a batttery terminal. Not the terminal but a wire into the clamp. Neighbor found it after I was at wits end.[/quote:cebdqld5]

I've had that on OEM multi battery cables. Always the second one it seems where the terminal kind of fits over the cable and is crimped on 90 degrees to it. I usually just do away with the lead post batterys, install stud post batteries instead and solder and crimp a new end on the original cable and make a short cable up to go from one terminal to the next. 

That's where a temp gun is handy as well, crank it for thirty seconds or so and point the gun at the connections, the bad one will almost always get warm and read higher than the rest.