I got a pair of rear seat belts out of a small Korean car, retractable, the car had not been in an accident and the belts worked fine before I removed them from the car, I knotted the belt to stop it winding too far back into the reel. Now when I try to pull the belt out more it just locks up (as it is supposed to in an accident), both belts are doing the same thing. I've tried turning the reel around, up, down , sideways but it still locks, (yes I know that the belt must retract a little before pulling it out but that isn't doing the job) I can't see any trigger to release them so it's not much use installing them in the car till I can sort the problem. Any help, suggestions greatly appreciated.
Not that it makes a difference but they are going in the back of the vert to replace the lap only belts that are in the car as standard, I'v found factory points in the back to fit the sash section, and even though I tried I wasn't able to find new belts that would do the job, these ones look like they have never been used as does the back seat of the car I got them from.

Try swearing at them in Korean?

I got some new retractables for the back of my bug a few years ago to replace my standard lap/sash ones. They were made by Klippan for the back of late model beetles. I was actually getting new front ones, and the bloke at Autobarn was looking up what I needed, then asked front or back?. I didn't know they did back ones for them, but he said they were listed. I got them and they installed OK.

They do fit to the same bracket that the standard belts fit to on the C pillar.

Yeah Jeff, seems that they won't fit the vert ( no pillar ) the place to fix the belts on a vert is on the panel just under the window and out on the side,when there's no belt fitted there the fixing spot is used to hold the carpet in place.

Do you know what angle the reel is supposed to be mounted at?

The angles it will not operate properly from will are very close to its correct mounting.

They really need to be clamped tight to work correctly......holding the reel in your hand usually won't cut it

Thanks hellbugged, that got me to thinking, went back to the place I got the belts from and solved the problem, they are fitted at an angle that I hadn't thought about, stuffed if I know what will happen if I'm parked on a hill as the angle seems to be very critical

Inertia belts use a pretty sensitive ball and spring locking system. Basically if the reel is installed at anything other than the angle which centres the ball in the mechanism then is activates the locking mechanism.
So you have to play with it until you find that angle, oh and in all 3 planes of motion not just 1 or 2 so more like angles.

I'd suggest a small spirit level, a protractor and a revisit to the vehicle you got them from so you can get a better idea of these mounting angles.