If you have had to lower the rear seat in order to make more room and then found that the seat belt was locked when you tried to raise the seat then try this;
Trace the seat belt back to the point that it is anchored in with a bolt and undo the bolt (using a ratchet is the easiest way due to not having much space) then raise the seat back to the uprght locked position and the seat belt should free itself.
Good luck!
Once you do this and before you let it down again, go to the dealer and get a replacement seat belt stop pin and replace the missing one. If yo look close you will see the hole where the missing pin used to be.
Pull the vinyl cover off of the seat belt, then roll the seat belt back on the roller.
All Volvo cars have seat belt. Volvo invented the three point seat belt and has used it ever since.
ELR - Emergency Locking Retractor..Seat Belt Retract you when you face collision.
bad retractor
The only why to repair the seat belt (retractor) is to replace the assembly,no parts are available to rebuild this assembly.
there is a recall for this
replave retractor
These parts are only fixed by replacement.
volvo
You will probably end up having to replace the belt as I don't think there is a way to tighten it.
Well, have to click the botton to unlock it
something stuck in it, if you can't get it to work a used one can be obtained from your local wrecking yard