Replace the latching part of seatbelt (not the piece on the strap, the piece bolted onto the side of the seat). That usually does it for GM's. You could also pull the fuse labeled "Chime" (or whatever it says).
On my 2000 Astro there is a small button just below and to the left of the headlight switch. Push that button four times in a row and you will hear a chime and the automatice headlights will be disabled. Tricky, eh?
http://www.silveradoss.com/forums/index.php?showtopic=3033
the seatbelt chime and door chime is hooked up to the stock radio in all gm vehicles just find somebody that knows car steros
MUST REPLACE FACTORY CD PLAYER OR CUT OUT THE SPEAKER LEAD.
To disable the chime in a 2000 Chevy Malibu, locate the chime module, which is typically found under the dashboard. You can disconnect the module or remove the fuse associated with it, usually labeled for the chime on the fuse box diagram. Alternatively, you can also address the cause of the chime, such as ensuring doors are closed or seatbelts are fastened. Always consult the owner's manual for specific instructions related to your vehicle.
if you have the owner book that came with the vehicle, you can find in the book how to disable the door chime
The chime can not be disabled or removed.
instructions to disable chime can be found in the ownere handbook that came with the truck it is disabled thru the computer in truck
Buckle up your seat belt and the chime will go off.
To disable the door chime on a Honda Ridgeline, locate the vehicle's fuse box, which is usually found under the dashboard or in the engine compartment. Identify the fuse associated with the door chime; this information can be found in the owner's manual. Remove the fuse to stop the chime from sounding when the doors are open. Keep in mind this will disable the chime entirely, so be cautious as it may affect other functions.
The manufacturers don't want you to.
Buckle up your seat belt and the chime will go off.