No crank from key

I have been going back and forth with this truck. Worked great then one day went to go to work and it would not fire from key switch. Seemed like a fuse blew. All fuses tested good multiple times, replaced battery, replaced starter and solenoid, neutral safety switch, and finally ignition switch. I now have a dead man switch that cranks the truck. Truck runs great in the on position fuel pump and accessories all work. I am thinking it may be a ground I am having other electrical issues at this point. Blower motor intermittently cuts out. The radio and equalizer both work but no sound out of speakers. Let me know what you think. Also, tester inline fuses directly off positive side of battery and didn't see any burnt wire on fuse-able links on firewall. I also changed the ignition control module. Forgot about that one. When I turn the key to start all interior lights dim and AC and radio turn off, but outside headlights do not dim. This thing has me all kinds of flustered. Hopefully I am reaching out to better mechanics than myself. All help is appreciated.