I had a slow cranker this morning also.
I measure it right at the battery and it was showing 11.5 volts.
A good battery should hold more than 12v from a charge overnight.
You need to test it while cranking, this simulates the "draw" test that parts stores would put on a battery.
I put on the charger for half an hour and it was up to 12.70, it started fine then and the meter in the dash was showing 14 volts with no electrical stuff on.
How accurate is the dash one, what exactly is it measuring?
Dash one is notorioursly bad at giving a good measurment, it is downstream from a bunch of other stuff in the electrical, and it missed the quick jumps and dips a good voltmeter will give you.
I'm also wondering if my battery doesn't like the cold weather or if my alt is going south and wasn't keeping it charged.
No battery likes the cold, which is why they fail more often when the temps drop.
One other possiblity I guess is I left it in 4wd last night when I parked it but i can't see that drawing on the system unless there is a short somewhere in the switch for the mode light in the dash (242).