Truck involved in accident and seat belsts are locked... whats the fix?

The SAFEST thing to do here is to just REPLACE them! Depending on how severe the 'Accident' was you may not be able to repair it. When triggered the mechanical parts the seat belt work on 'Lock' and on most models cannot be released.

after a seat belt being stressed that much in any accident it locks out

almost every 3rd world country would say the seat belt should be replaced with a new one

if its you or passengers wearing that one .. ..
better idea to have reliable safety belts
than a head going through a windshield

You should not try really. A seatbelt should be replaced after an accident like that.
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by law seat belts cannot be repaired so to comply , replace it as a unit
many seat belts become frayed on the edges from use and the common fix is to run a lighter along the edges to reseal the nylon fibers
This makes the seat belt weak and increases the risk of failure and injury in an accident to an unacceptable level
If a vehicle has been involved in an accident it is a requirement by law to replace all those belts that were in use at the time of the accident

I used a can of degreaser and with the little straw sprayed inside and it loosened up the gunk stuck in there and it works great now

This should be replaced. It is an eletronic part and will malfunction after accidents.

If the vehicle was involved in an accident, the belts will then lock up permanently, requiring them to be replaced. Might be what's wrong with yours since they don't usually go bad in pairs, unless in an accident.

THERES BOLTS EITHER ON THE BOTTOM LIKE A FOOT AWAY FORM THE DOOR, OR THERE GONNA BE BETWEEN THE BOTH SEATS BY WHERE YOUR SEAT BELS GO IN. YOU HAVE TO PUSH OPEN IN THERE AND YOULL SEE THEM THEY SOME TIME HOLD THE SEAT BELST ALSO AS WELL AS THE SEAT.

you remove them and unlock the gas release on bottom of seat belt but I would suggest getting used ones from junk yard.

if the light does not go off there is somthing wrong they might have to replace the seat belts the seat belts have triggers in them when you get in an accident the triggers go off and they need to replace