Did the buzzer ever work? I know people that have disconnected the buzzer because it annoyed them. its located under the steering wheel compartment. First i'd check my fuses. I've heard that they go bad sometimes. Good luck. On the light subject most likely the bulb was removed, I've removed couple myself. its just annoying( i removed the srs). I wouldn't remove an important bulb like the oil one unless i knew there was a problem and put the car for sale.