I am giving this another quick update.

I did install a new alternator (and ended up going with the Mechman 'high' output (240 Amps).

It improved the voltage, but it is still stuck under 14 V (temps have been between 14 and 35 F). I saw the max read 14 V once.

I recently got an MM3, and when I grabbed the DTCs, a new one popped up and lost connection to the intelligent battery sensor.

That one did NOT show on my little OBDII/Torque Pro app.

That was also the ONLY DTC showing on the MM3.

I will check the grounds and the crossover cable this weekend and then replace that sensor.

Again, I will update the initial post once I get this sorted.