To begin with, inspect the seat belts, buckles, latch plates, and guide loops for any obvious damage. Ensure the seat belt reminder light comes on. The seat belts are designed to lock up during a sudden stop, yet allow free movement during normal driving. The retractors should hold the belt against your chest while driving and rewind the belt when the buckle is unlatched. Also, if any of the above checks reveal problems, replace parts as necessary.