All, I have a 1995 F-250 7.3L. Ignition switch cylinder was bad, so just replaced. Now goes to start and auxiliary without spinning 360-degrees. That's a good thing. Bad thing--when in start position it doesn't start

In run position, I can jump it from the fender wall solenoid and it purrs like a kitten. Just won't start using the key! Pulled dash apart to check for lose, broken, dangling wires. None found. Truck runs all day in run position and shuts off when I turn the key off. Just won't start. And yes, solenoid on fender wall and starter/solenoid under the diesel are brand new.

Any ideas????

 

Could be a few things. Behind the key switch there is a little gear cog that engages with a rack, the teeth on these may be bad.
The ign switch is bolted to the steering column under the dash, it may need adjusted. You could try loosening the two bolts and sliding the switch down the column a little to see if that helps.
It could also be a bad neutral safety switch. Try starting it in Neutral instead of Park and see if that helps.