Riding Lawn Mowers

new 3-bin bagger on gt245xl 48" has a bag full indicator..its a little wheel that stops spinning when no grass is going thru..it doesn't work..I guess its suppose to draw air in and me the wheel spin that way..there is a windage tray right before the hole that sucks air in making the wheel spin...again it doesn't work..dealer says no one else complained....

any help...I'm thinking about drilling a hole thru the windage block and help the draw thru the hole....