Cars in the early 1970s

Factual Questions
21

Our next door neighbors had a car, IIRC a 1970 Pinto, that could sense weight in the(driver’s and/or passenger’s) seats and would sound a buzzer if the seat belt wasn’t buckled. I learned this when I asked why they buckled-in their groceries.

In a Mopar magazine, a guy wrote in to ask about a device he’d found attached to the firewall of a classic car he’d just bought: it wasn’t attached to anything anymore, and it didn’t say what it was on it, and he couldn’t find it in any of the manuals.
The editors replied that his car was a 1972 model year, and the device was an interlock that would prevent the engine from starting if the driver’s seat belt wasn’t fastened. They said this had been required by a federal regulation that had lasted “roughly until members of Congress started taking delivery of 1972 model-year cars”, and then they repealed the regulation AND made it legal to get the thing disconnected.

My experience with older cars was that warnings were a buzz not a bell, as others have stated above, and I regret I can’t say exactly which years/models had them.

22

The reason cars of the 70s ‘buzzed’ instead of ‘dinging’ was because they used piezoelectric buzzers. Being electro-mechanical devices they had a very limited and harsh sound. By the early 80s these began to be replaced first by less harsh electro-mechanical chime-tone devices then by the late 80s (to today) fully solid state electronics which can be custom designed to make a variety of sounds.

The primary motivation for this was manufacturing costs. Slowly but surely solid state electronics became much, much cheaper to mass produce than electro-mechanical ones. It’s the exact same reason mechanical ignition lock cylinders and uniquely cut metal keys are slowly being replaced with push buttons and.electronic key fobs.