ok so here we go i have 99 d with a 5.2 mag lately the truck will just shut down by itself then wont crank when i turn on the key the guage says no bus and the gauges wont show the batter fuel or heat and the auto shut off relay is going haywire clicking like hell if i pull it out and put it back in it stops but wont crank

then if i lift up the fuse box it will crank so i thaught it was a loose wire so i took the fuse box apart and checked everything and nothing all wires tight and clean no burnt and the ground by the box is tight and clean
what could it be?

 

The 1999 has known issues with the PCM. They like to go out and do not like heat. Try to put a bag of ice on top of it and see if the issues recide, if they do then replace the PCM. If not check your wiring harness at the PCM for corrosion. Also check fuel pressure and the coil.