24=Safing Sensor Output Feed/Return Circuit Open
Safing sensor output? There is a sensor either in the seatbelt latch or the seatbelt assembly in both front seats that tell the restraint control module if the seatbelt pretensioner has been activated. Either you had an accident and the pretensioner was tripped (least likely) or the wiring connection is poor (most likely). I believe this is what an airbag flashing 24 should be at least according to the last Ford service manual I looked at. Hope this helps, I will double check at work tomorrow.
L8R
Scott