I have a 96' K/1500 305 that will not start

I have a 96' K/1500 305 that will not start. None of the lights will come on except for the center interior light. When the key is put into the ignition the chime will barley sound and when the key is turned nothing comes on. The only then that happens when the key is turned is the gear shift indicator lights up. This problem was eluded to by starting and the truck cutting off a couple seconds later and cutting off with no warning at intersections. I replaced the ignition switch thinking that was the problem but it did not fix. Also I checked the main fuse box and it is only getting around 6 volts, the same reading can be found at the ignition switch. What can be causing the main fuse box to only get 6 volts? Please Help