have a 97 lincoln town car executive. it makes a snapping sound behind the radio and seems to be above the heater box. i pulled the fuse for the climate control and it stops. the fuse controls the climate control and reverse and signal lights. to me it spounds like one of those little gears that open and close heater doors slipping. just asking because i dont want to take the heater box out because it is very hard to get out.