No electrical power to anything

Initially, truck sporadically kept cranking only way to stop it was pull battery cable off. After replacing starter, solenoid, key ignition, ignition control modular headlight switch pigtail, alternator. Still didn't fix it. Drove truck shut it off I went to start it again, completely dead as if I had pulled the battery not even headlights. I then replaced battery, new battery cables, relay switch, replaced ignition modular again and replaced ignition again. Tested starter it was fine and checked inertia switch. Also checked all grounds were good. Still dead. Been using probe tester only positive wire up to the starter relay. After that all wires stay green. The signal wire from the ignition switch stays green too and it is supposed to have power. Can that be causing the whole truck to be dead? And what does that wire connect to? Any other ideas? I'm stumped!

I just bought a 1986 f150. It is a stock factory vehicle with a 302. The starter relay was bad and the original owner had unhooked the wireing from it. There is no power to anything in the truck, no headlights, door buzzer, nothing. But the battery is fully charged.I would like to know which wires conect to to what side of the relay cause I think this is where the power starts. There are four wires in question and I will describe them from the end connecters to the harness;one black 16 gauge wire with a that plugs into the harness. One red 16 gauge that goes to a black fuse link and then becomes yellow, one black 16 gauge wire into an orange fuse link into black wire, one blue 18 gauge into black fuse link then becomes a yellow 18 gauge.I have already donated and I thank you.

Cranks from starter solenoid but no power from key ignition. So I have no dash lights and no other power from the key ignition. How can I fix that?

Okay, thanks.

Okay, but will this give me power back to everything inside the cab of my truck?

I have a new starter, starter solenoid, new key tumbler and ignition switch, and battery, but still no power inside my cab?

Okay, I checked around some more like y'all said and came across this and they looked burnt and had no power to them.

Okay, fixed the no power thing. But now when I turn the key the starter solenoid just clicks no crank.