air bag light will not go off. had replaced several things and im wondering if I

I don't know if you changed anything with the seatbelts. I know it sounds kind of funny, but a friend of mine worked at an auto body shop and the owner who has many years experience told her that it was a sensor in the seatbelt. Either in the part that you click into or the part that you bring from your shoulder. There are sensors in them somewhere (I am assuming Fords are like other makes) don't know for sure, but wanted maybe give you some help.