Celeste
My fan was rusty too. So I removed it.
A few of us have filled in the resulting hole with 12 volt computer fans. Mine are very small and don't move much air. Other people have put in bigger fans. It is a good way to give you more space over the cooktop while removing the cooking odors and steam and stuff. But you have to design and make your own.
You can just barely see mine behind the rack with the spoons. Tiny, but they work well.