I have a 2002 Impala whenI start the car security lights up and stays on it also saye see dealer door locks,seat belts and trunk keep clicking open and seat belts bells.it also happens when I turn car off.Can anyone help.

That secuity light usually means the Anti Theft System doesn't recognize the ignition key.
Call local shops and tell them what's going on and they can tell you if they can diagnose your vehicle. Otherwise, you may need to go to the dealer.