Seat belt retainer broken? Locks you in too tight!
 

96 sl500 the passenger seat belt retainer seems to have a problem. I can pull the seat belt closed all the way and it will unwind all the way even past where I need it. But once its clicked in and the retainer takes out the slack, it takes out all of the slack making it very tight and gives no slack at all, causing the passenger to be very uncomfortable.

Is there something I can adjust or do I need a whole new restrainer?

is it possible that the child seat feature is on, or malfuntioning? look on the side of the seat by the door, some models have a switch there that will lock the belt. that may be what is happening

In addition to the switch that Carson mentioned, check fuse #3 in the trunk. If all that is well, then you have a problem with a relay in the belt take-up reel mechanism, wiring, or the convertible top controller (it controls the relay in the reel).

Definitely check that switch. I couldnt figure out what it was at fist (too lazy to read the manual), and switched it. I had the exact symptoms as what you have!

Thanks guys, you are all great. I will check it in a bit.

It was the child restraint switch!! Once again you guys save me cash. I could not see it because the switch had worked loose and fallen inside the seat track cover.