Originally, they didn't start without the seatbelt on. These cars are 30+ years old, there is no telling how people have rigged the systems over the years to make the car start without the seatbelt..
My 74 also starts just fine without the seatbelts on ... must have been rigged at some time or another ... heck ... even the Chiltons has instructions on the bypass procedure. My car did have a buzzer reminder that I removed ...
It had something to do with the wires under the seat. If I remember right, if you short them together it will start without the belt and buzz.
Where did that come from? Ever wake up in the middle of the night with a thought in your head? This thread popped into my head at 4:30ish this morning. Something told me that if you add a key switch-sort of like the old security systems used with the lockbox key, that this seatbelt interlock system could be used as an anti-theft system. I'm going back to sleep now!
