buddha,
I think, because the battery in the truck is dead...electrochemically dead. It cannot pass the the current from the donor battery through its cells. If you left the jumper battery on it awhile, it would probably start the truck. I have tried to jump start rigs that had a dead battery, and sometimes, it just doesn't work.
Right now, I wouldn't focus on the jump start question. Use that time to have the battery load tested and/or charged. If you want instant results, put a know good battery in and see what it does. Make sure as you explore your system that you have good strong grounds from batt to frame and engine. Keep going, you will win!
I didn't ask, but I assume you have actually started this truck several times before these problems occurred..you mentioned driving around and have fuses popping!
Stuart
