steering column/ignition key lock

I've lost the "action" in my ignition key cylinder and don't know why. The key only moves freely forward to it's furthest position and then back the same way. There's no "spring" feel to it and no stops where it would be in acc. run or start. When it is moved to start, it doesn't snap back to the run position like it should. I've pulled the steering colum and pulled a different one out of the jukyard. I removed the steering wheel and lock plate at the yard, inserted a new key cylinder to check for proper action and it had it. HOWEVER, when I completed pulling the column off the wreck, the action, stops and feel are no longer there. I'm back to square one and don't know what I've done that it should work or feel right on moment and not the next. Up a tree without a truck. : ( Thanks for any help!

What year truck is this?
If it has an ignition switch located down on the base of the column, the rod may have come loose or the switch is worn out.

It's a 1980. I'll check the switch and see what I can find. Thanks!

Faulty switch and bad rod. Replacement column solved problem. Thanks!