Well, it sounds like the starter is not the issue. Our ground cable is a decent size at the starter and it's a elephant ear setup so the motor should be grounded pretty well. Although, the battery is grounded to the frame, wonder if that could be the issue? I think the voltage drop test is going to be the next step. Thanks for the instructions.

Ron, I'll mention something to Dad. He probably knows the procedure for the voltage drop but, I'm sure he would take the help.

We are also going to try throwing a ton of voltage at just the starter with two batteries.

I have a feeling we're going to find a voltage drop issue. When the starter hangs which is only on a hot motor. Everything is drawing down (lights, pumps ect....)