WHILE PULLING UP TO A LIGHT CONSUMER HIT ANOTHER VEHICLE IN THE BACK, AIR BAG DID NOT DEPLOY. SEAT BELTS WERE WORN AT THE TIME, BUT SHOULDER BELT DID NOT LOCK HOLDING OCCUPANT. THIS DEFECT CAUSED OCCUPANT SUST INJURIES. HEAD WENT THROUGH WIN SHIELD TWICE, BOUNCED AGAINST SEAT, MINOR BRUISES. FORD CLAIMS SHOULDER BELTS WAS NOT WORKING PROPERLY, LAP BELT WAS WORKING. THIS DEFECT CAN CAUSE BODILY INJURIES IN CASE OF AN ACCIDENT. *AK