S320 : Seat belt problem. Can anyone help?
 

Can anyone tell me if they know of a fix or how to get into the seat belt tensioner on an S320?

The belt is all the way out, and it will not go back in. Is there a way to reset it? Or, do I need to get into it and work a fix from there? I need to know how to get into the door pillar to fix it...Thanks for your help.

Dont mess with it. It is part of the SRS system (airbags) and you could get real hurt trying to repair it.
Replace the assembly.
However. it could be bound up behind the b pillar.
To remove the pillar, Move the seat all the way foward.
Remove screws from plastic panel at base of pillar.
Remove front and rear door sill plates (pull straight up).
Remove door frame seals (the fabric covered ones).
You will see four metal clips on the plastic panel and four more on the pillar. Detach them from the door frames.
It is now able to lift out.
Be sure to line up the seat belt height adjuster when reinstalling.
Brian