Oh, that totally sucks.
I hope you are able to talk to someone who is willing to fix it for free.
I had the motorized shoulderbelts in the front of a 1991 Honda Accord, I was always worried about them! They made such awful noise for one thing, and sometimes they would run soooo slowly that I just knew they would break (they never did).
Just one more reason it sucks having to drive an older vehicle. I worry all the time that my seatbelts aren't safe in the 1994 Mazda MPV that I drive now. They just look dirty and old. We were dreaming of a new vehicle this new year, but it doesn't look like it's happening. We need to spend roughly $500 on new carseats (and tether anchors) for Hayley within the next month or two, pay off a laptop (computer, not child restraint, LOL) and learn how to stay on a budget. Maybe this time next year we can get a newer, safer vehicle.
Now I'm done rambling. Good luck to you!