Starting in the morning after sitting all night after about 50 degree nights, my key on voltage was 11.6 and FICM was 48. My alt is good, driving it charges mid thirteens to fourteens. Is that normal

 

The glow plugs are drawing 160+ amps, hence the low voltage KOEO

At the batteries you should see 12.6+ volts above 50 degrees with nothing on.

Charging you would want to see 13.4+ volts at the OBD port, ideally you want 14.0+ volts at all times.

Josh