Panderz

It started out as only happening sometimes that nothing would happened when I turned the key, but sometimes it would crank normally then just stop even though I had the key turned. Now nothing happens at all every time I turn the key.
I started out thinking maybe the eyelets connecting the starter to the battery were dirty so current couldn't pass through so I cleaned those. Reconnected them and still the same thing.
Pulled the starter off to have it tested at autozone, they gave me a new one. Installed the new starter, still nothing.
Stuck a screwdriver on the connections to the starter and it cranked over just like it was supposed to.
Wired the wire that was hot from the ignition right to the starter connection and connected the battery, started turning over like it's supposed to. Thought maybe the starter relay is bad so I replaced that. Still doesn't work like it should.
I'm really losing my mind over this and don't know what the next step is, some ideas would be a great help.
The battery is also less than 3 months old so it's not that.

Panderz

All lights, horn, and fan work just as they should btw. Literally the only symptom is that nothing happens when the key is turned.

Coronet 500

Check the wiring where it goes through the firewall.

Panderz

everything looks intact, none of it was messed with except to replace the relay

Panderz

also when I turn the key with the ac on/lights on, ac stops and lights dim so don't think it's a bad ignition switch

Panderz

So I bypassed the starter relay and jumped a cable between the ign. switch and start solenoid leads and then turned the key and it cranked just like normal. I have no idea what to do next.

64Imperial

Them wires on the firewall if you have plugs like mine unplug them they could be green a and corroded on the inside mine looked fine just looking till i unplugged them.

I cleaned them like new below:
mix a bowl of White vinager and poor salt in it and stir, keey adding till it wont disolve anymore salt,
Mix another bowl of water and baking soda do the same till it wont disolve baking soda anymore
sit the whole plug in the vinager salt for 2-3 minutes, use a brass brush to brush inside and outside whirl them around and get all the junk off
now sit the whole plug into the water and baking soda this till sterilze the corrosive properties of vinager and pull the rest of the crap off
after you do this i would grab a garden hose and spray it all off really good if you dont kill the vinager it will corrode worse than it was before you started in like 45 minutes just make sure you rinse good.

how to video below:

BTW i cant spell vinager it seems lol