1986 200SDL floor vacuum is #3, third line down.

Do you have no heat on floor at all, or just not driver's side?

I lost driver's side, see this thread.

Right floor heat OK, left floor none

Loss of driver's side, but no passenger's, seems to be all too common, do a search, there are other threads.

Do a check for vacuum at #3. If you can remove the radio, you can see the vaccum pod and linkage, and confirm that it moves, or doesn't.

Let us know what you find.

Best Regards,
Jim