Ignition switch sticking

[F100 Dad]

When I turn the ignition key from the Off position to crank the engine it "hangs up" or "gets stuck" and won't turn to the crank position unless I wiggle it back and forth several times.

Do I need to replace the lock cylinder or the ignition starter switch?

If either of those are not a common failure item, what can I do to determine which I need?

1970 F100

[sargentrs]

Just the lock cylinder or the key itself. You might try lubricating it with some WD40. Stick the tip of the key in then spray in the lock and work the key back and forth/in and out. See if that helps. Or pull the lock cylinder out and lube the pins. While it's out, stick a screwdriver in the switch and see if turns easily. If so, get a new a new key made first before spending the extra money on a lock cylinder. Better to throw away $2 than spend money unnecessarily. And don't forget, if it's original that's the key to your door locks too.