Truck wouldn't start but I found the problem and wanted to share so maybe someone else wouldn't suffer much.
I had a fuse blow on my trailer/exterior running lights "chicken lights" as they are lovingly referred to, so I replaced them with a fuse from the 4x4 part of the box. I have 2WD so there's no use for the 4x4 fuse. Boom, all my twinkly little lights all over the truck fire back up and I go have a beer in celebration. This morning I go to leave for work and nothing. Put the key in, let the glow plug light go out, turn the swith and nada. It doesn't even attempt to turn over. I check batteries, grounds, cables, fuses, ALL of the fuses and find nothing. 2 hours later I realize that the only thing that has changed was that fuse I messed with regarding the trailer/exterior lights.
It turns out (long story short) that even a 2WD truck needs a fuse in the 4WD slot!!! I put a fresh fuse back in there and the old bruiser fired right up. If I would've tried to fire the truck last night after my experiment I may have been a bit quicker to put things together.
Bottom line, never assume a fuse is not doing anything even if you don't have that option!