Is there also a light over the rangetop, and does that work? This could be a clue to if it is a fuse/wiring problem or a fan motor problem.
Look at all exposed surfaces (including with filter removed) for a manufacturer/model number of the vent hood, or call Heartland Service with you VIN number at the ready to get this info.
There are manuals in the "Tools" tab in the home menu on this forum. Small parts like the fan motor are usually available on E-Bay.