This morning the turn signals stopped working. Flashers still work.
When turning the turn signal on, the indicator light on the instrument cluster does not come on.

On all the other cars I owned when the flasher stopped working, or a bulb went bad, the light on the dash would stay on and the actual blinker light (if still functioning) stayed on. Does this indicate there something wrong in the switch itself on the column?

See the attached turnsignal schematic. That the 4-ways work show that the lights and flasher are ok.

The diagram is shown with 4-way off. 4-way power comes from Fuse 11. Turnsignal power comes from Fuse 9 through the ignition switch. Check fuse 9 first.

Excellent. Thank you for the diagram.

Just checked #9 fuse, looked ok. Turn signals worked this time, too. Replaced the fuse anyway only because I had one handy. Looks to be an intermittent issue.
Turn signals light up with the ignition off, so it's not anything in the column.
Flasher relay?