1998 Jeep Grand Cherokee seat belts problems

Jeep grand cherokee was involved in a virtual head-on collision with another vehicle. Other vehicle was traveling approximately 35-45 miles per hour. The air bags did not deploy, nor did the seat belts lock upon impact. Crash resulted in minor injuries to driver and passenger.

1 driver getting into the drivers seat, preparing to leave by buckling the seatbelt and pushing it firmly into the buckle lock 2 the cause is unknown after many failures, as the belt simply begins to wind back to the b-pillar as if the driver had just exited the vehicle. No noise is made, no force needs to be exerted on the belt to recreate the failure, in which recreation is impossible. Often failure may occur after an extended amount of driving time. 3 unknown to date.