John Deere 2150 electrical

[Joe MD Barrel Horses]

I need some help with my jd 2150. When i try to start the tractor the gauges come on but engine will not crank. I replaced the starter solenoid but gthe problem persists.i can arc it acsross the back of starter and the engine cranks no problem. just trying to see if anybody might have some suggestions for me as i am at my wits end. Thanks!
 

[Tx Jim]

Remove tin cover over trans that gear shift levers protrude through, locate switch(nuetral start switch) with 2 wires attached and try removing one shim washer,reconnect wires and crank engine.