In the majority of modern cars there is an electronic signal that goes off when the seatbelt is not secured in. As long as the seatbelt is locked in place, then nothing happens, but if the key is in the ignition and the seatbelt is not plugged in, then an alarm or beeping will go off either consistently or periodically. You can disable the seatbelt warning chime at home by disabling the signal wire. On the Mitsubishi Lancer, the wire runs up the side seatbelt receiver.
Locate the wire that runs to the seatbelt receiver, also known as the female-end. This wire is what tells the car that the seatbelt is plugged in. Running up the side of the receiver closest to the seat is a thin wire. You can access it by pulling the seat cushion to one side. When the seat is pulled out of the way, you will see the wire, just below the level of the seat cushion, on the belt receiver.
Cut the wire that runs to the seat belt with the wire cutters. Cut it close to the seatbelt receiver, but leave enough space to secure it again, if necessary. Usually an inch or two is ample wire to leave behind.
Route the wire to somewhere that you can ground the wire, such as to the metal frame of the car.
Tape or solder the wire to the metal frame so that it is grounded. This will make the car think the seatbelt is always secured.
