Why isn't my quill stem controlling the front wheel of my bike?
Completely remove the bicycle quill
Hang the bike up-side down
Take out the wedge. If the wedge is stuck, try inserting the quill bolt alone (no quill, just bolt). Take care not to push the wedge further in. Try to thread in the wedge, and remove the wedge when there is enough grip.
If wedge is truly stuck, remove the front wheel from the fork. The fork should have a hole so that you can push the wedge from below (with rod/hammer)
Re-assemble the quill and wedge with the bolt correctly. Make sure you know how to do this, it should be straight-forward.


Good luck

Bicycle terminology (regarding quill stem, which often seen in old bicycle):


Wedge (sometimes 'Expander'): a device that wedge/expand the quill inside the fork steerer tube. This is achieved via compression of the wedge/expander into the quill, using a quill bolt.
Quill: a device connecting (fork) steerer tube and stem. Usually the stem and the quill comes together as one part.
Stem: a device connecting the handlebar to the fork (via quill).