Pulling along headed for the supper plate at the end row and half way through the field it lost all electrical power and died. 

I checked the main breakers and they were good.  Had power to what the parts book calls a "switch magnet", but not on the other side of it.  Have power to the starter.  But those are the only place I could get power to. 

Chasing electrical problems in the dark with a cold N wind blow down my back, I gave up for the night at that point.  Will face it in the morning.  

Does anyone have any ideas where to look?