I think something is stuck inside the seat belt buckle but I can't see anything but I can't buckle it either. i've tryed shaking it but nothing is moving around inside it. The seat belt is in the back seat. I have a 2000 Saturn LS. is there a way to fix this without replacing the whoe thing?

please open the buckle assembly. Pretty sure something is stuck in it. clean all parts and reassemble.

I’m happy to assist further over the phone at https://www.6ya.com/expert/uttamjeet_2f3adc18600f8ede

The mechanism has jammed so find the mount at the bottom near the lower sill, unbolt it from the vehicle frame and shake it until it releases. If this happens, reinstall it. If it will not come un-jammed, it will need to be replaced

On my 2016 Ford Escape the rear passenger seat folded down and would not hold back up the problem was that the seat belt buckle pivoted down below the level of the seat when I try to raise the back of the sheet the seat belt buckle would prevent it it ended up crushing the plastic on the seat belt buckle preventing it from working the hold the seat belt I was able to repair the seat belt buckle with a screwdriver regular Style and a cigarette lighter the soft in the plastic back up so it would stay in position

hi.
i think your dealership is lying to you.
the warning should not sound if your belt is done up. there IS a problem somewhere.

the first thing to try, is make sure there is nothing left on any seats, and then to buckle up ALL of the seat belts, as it may be a sensor on one of the other seats telling the car that someone is in a different seat.

if this stops the warning, then undo the seatbelts one at a time until on of them sets the alarm off.
this will tell you which seat has a problem.

then go back to the dealer and tell them which seat is causing the problem..
if they still insist there is no problem, ask for the manager and explain exactly what is happening

sensor may be stuck inside your seatbelt. spray a lube inside it and put it together and take it apart 5 or 6 times just to get it to loosen. do this to the passenger side as well. if this doesnt work then some cars have a sensor built into the seat that tells the car you have a passenger that isnt buckled. its possible that this sensor is stuck. should be located under seat but can be checked by simply buckling the passenger seat belt and seeing if the light goes out.

I guess you answered your own question.

Personally I would consider this a God send, but in your case lets see if we can find the problem.

Has anyone worked on the car recently?

On that new of a car the only things that could cause this problem is a wire disconnected or cut or the body computer acting up. Sometimes a radio source (cell phone) too close to the computer can cause malfunctions, but that happens mostly in dodges.

Check under your seat for a wire disconnected, if nothing then see if you can find someone that can scan your body computer to see if there is anything there.

Check down in the seat belt re-tractor, many times things like pennies get in there and jam it, remove the re-tractor and shake it, if nothing comes out you will have to replace the seat belt, of course I assume you are not talking about the buckle release button being stuck, if so you still will need to check it for foreign objects.

Soak it soak it and soak it....... may take a few days.... If nothing works, get a hair dryer and heat it up warm to the touch..... melt wax all over the quite warm bolt unit and let sit overnight.... as it cools it will draw the wax down along the threads