Heater controls 101. Plus, I'm not sure windshield vent is actually working.

[sugarwood]

Yea, they turn on when you pull up the levers.
It's a small project. 3 screws to remove the cover.
Fuse probably blown (10a)
Just remove the break the fan free.
Mine was stuck from years of non-use.

The hardest part is replacing the cover.
lining up the holes for the screw.
I use a coat hanger to line up the screw hole.