Will not crank over

[Speedrcr]

I'm now at my wits end with our 1993 Camaro. We had a bad starter so we changed it for a new one. While adjusting it with a shims and having to clearance the convertor shield that car was turning over and then all of a sudden it stopped cranking over.
Figured we ran the battery down....charged it up no change. Heard the click from the tdr in the dash and the starter would buzz. Changed the starter again..still nothing. Checked the key, and the resitance on the lock cylinder...passed. Put in a new theft deterrent relay, checked the voltage at the relay, etc...still clicks, starter buzzes, nothing else.
Now the fans turn on when you turn the key to start, still getting a click from the relay and a buzz from the starter. Heck out of desperation we changed the battery and the computer....
This is killing me!