Just replaced my seat covers and foam. Thanks to all C3VR posts and techniques! Anyway, now the seat belt warning buzzer is on all the time, except with parking brake handle up. It's on with nobody in either seat. Thought it was the passenger seat, but when I took it out, it was still on. Tried closing the contacts for the passenger seat electrical quick disconnect, but it still was on. Have replaced the drivers side seat belt a few years ago, but never the passengers side. Any ideas for the fix...
Thanks.    

What year model car are we talkin bout here?

On my '74, there are pressure sensitive switches on the bottoms of the seats, that do, from time to time, get stuck, and the belt light/buzzer come on. I have extras I could put in, but...I'm just too danged lazy! Pulling the park brake one notch will silence it, but then you have the red park brake light on...
If you unplug the switches(both seats), and the buzzer still sounds, then I would think the wiring has shorted somewhere, most likely along the rear bulkhead behind the seats, or possibly a pinched wire under the seat itself.

Unplug the driver side switch, and see if that is the one that is stuck...if the buzzer stops, then plug the pass seat into the driver side plug, and see that it stays off. If so, then you know the problem is in the driver side seat.Adams' Apple2007-12-14 19:44:57

This is for a '72... The passenger side is the only side with a pressure sensitive switch. When I started all of this, I drove around without the passenger seat in the car and all was normal. I'm thinking right now that when I lubed both seat belts(by pulling them all the way out), maybe the electrical contacts broke. [Each belt must be pulled out a certain distance in order for the horn to go off]   On which belt, I don't know...