2005 mercury grand marquis air bag light not lite hear 5 chimes

Hello, The airbag light not illuminating is likely an issue with the instrument cluster. Normally, any and all issues with the occupant restraint system will cause the light to illuminate, ding, and stay on. Still, have the vehicle scanned by a professional scan tool to see determine what error the vehicle is reporting, and to determine functionality of the occupant restraint system.