Turn key and nothing, but all lights, horn etc work fine!

Try crossing the starter wires, it should turn over. Is key ok, maybe its not coded? Also check connectors on starter . Try disconnecting battery for 30 mins, might reset electrics.

What is a horn roter

Maybe the ignition switch burned up. A lot of juice travels through them and it has happened.
What is confusing is, lights will work without the switch. You should be able to turn lights on without the key in the ignition. But a radio normally needs the ignition turned to ACC (accessory) or ON. And some when left on don't turn off with the key off until the door is opened.

Possibly the ignition melted and is affected to where the radio still gets power as if it was in the ACC position

1989 f250 4x4 lighting problems. i replaced the floor mounted dimmer switch ,the lights worked fine for an hour untill i turned them off.Now the lights will not turn back on but i have park lights.

Owner's manual should have a diagram of the fuse panel. Need to find which fuses control these items and check the fuses.

starter/solenoid issue.

if its a factory alarm you put the key in and quickly turn the key on and of i cant remember if its 8 or 9 times but the horn will chirp then you push the lock and unlock on the fob the locks should respond then turn key off and your done. note that if you have more than one fob you have to press lock and unlock on all of them before you turn the key off and i believe you only have about fifteen seconds to do so if not let me know i will look it up at work

there are two seperate horns

its most probably the clock spring which you need to take the steering wheel off to fit

I suspect the ignition switch is malfunctioning.