Steering Column Repair: F-150 ignition switch problems

Question
I have a 1992 F-150, when I put the key in ignition and turn it to on position the truck starts by itself without physically turning the key yourself and when I turn truck off the dash lights stay on like key is still in on position. Is this a bad ignition switch, or tumbler, or blocker assembly where all these wires plug in then split off?

Answer

ford ignition switch f   Hi Shawn:

My best guess (and it's real hard to diagnose an electrical problem over the web), would be a bad ignition switch...the white plastic electrical switch mounted to the column.  That's a pretty popular part that fails and when it fails, it often shorts 2 circuits that should not be together (like run and start).

When you take it off, you may be able to see where it has begun to burn slightly and be discolored.

Let me know if that does it or if a new one does the same thing.