Autosteer in the 9370 has been faulting out occasionally.  Shows low system voltage...about 11v when its' working, at 10.6 it faults out.  Tractor instrument cluster shows 13v.  Gauge responds to turning lights on and gives an appropriate 12v when engine stopped.  Tractor starts.  Tractor dash low voltage light flickers often and illuminates if you try to run the lights, however the instrument cluster still shows 13v while the  voltage light is on.  

My first answer is as always: the power supply is bad.  However, this is hooked up to good 30a cab power, not a cig lighter or something else of questionable repute. 

My question would be whether there are two power sources supplying things in the cab.  That would appear to be what is indicated by my brief, in-the-dark preliminarly diagnostic attempt.  Does this sound like something that is plausible to those of you who have lots of experience in these tractors?