Seat Belt Warning Buzzer Won't Silence

[sutekh]

Hey Folks, I recently had my dash apart rebuilding my AC and after putting everything back together, my seat belt warning buzzer and dash light don't disengage unless the seatbelt is latched. Unlatch the seatbelt with the ignition on (engine running or not), and the buzzer sounds indefinitely. My recollection is that it's only supposed to sound for ~5sec, and then stop (regardless of whether the belt is latched).

I've double-checked that everything is connected securely, and pulled the relay module apart, replaced the electrolytic cap, and inspected it for cold solder joints--all looks well.

Anyone ever experienced anything similar? Can someone with a later US car remind me if the buzzer stops sounding when the key is in the 2nd position, the car isn't running, and the belt isn't latched? I'm wondering if the seat belt module it isn't getting the memo that the engine is running or something?

At least if I buckle up, it stops, but this new development is still annoying. I'm not going to disable the module entirely, as it also powers the dome light and I want the headlight buzzer function.

https://handbook.w116.org/cd/Chassis/54-410.pdf

[daantjie]

There were many iterations of this system over the years so you'll have to state year and model and region I would think.  I recall a section in the FSM with multiple pages of variations.