Manual or Auto AC.
If Auto - and its anything like the Idea - the resistor is part of the fan and is not a resistor as such but an electronic part - component on a separate bord..no clue if you can get it alone.
You have to take the fan out, open it..and there is the component..
If the fan stopped working, try hitting it with your hand..if it starts up - its probably the brushes and not the electronix..