1974 GM seatbelt interlock system video

Joined
Apr 27, 2010
Messages
18,203
Location
Suburban Washington DC


Got a few questions.

1) At 6:00 it shows an under hood bypass switch. While that was before my time, I don't recall ever seeing such a switch years later when looking at cars. Did that make it into production?

2) At 4:45 it shows her buckling the belt BEHIND the dog. Didn't most people who didn't want to wear belts themselves, do the same thing?

3) How many 16 or 17 year old girls of that era owned a new luxury car? Or have a baby, 8:00?
 
Most people here cut the wires at the seat belt and twisted them together to trick the system into thinking that the seat belt is buckled.

My dad did this in his 74 super beetle.
 
I do remember seeing the under hood switch on my Dad's '74 Vega. The system had long since been bypassed, like most '74s.
That was a '74 Impala with no A/C in case anyone wondered.
 
I had a 1974 Pinto that had the bypass switch. It had to be pushed each time you wanted to start the car, unless you wore the seatbelt.
 
Wow, didn't realize there was a passenger presence sensor. I've heard about these systems but have never seen one.
 
The roots of all the overly-complicated stuff they install today that requires a visit to the dealership to fix. What a pain.... if the car doesn't start, get under the hood and push a button. That's fun in the rain. I think the system was a little different in the 72 Monte Carlo we had when I was a kid. My dad pulled all the seatbelts out, rolled them up and tucked them in the crevice of the seats to keep the buzzer quiet.
 
72 was the first year for the warning lights/buzzer system. In my 72 GS all you had to do was disconnect the plugs in the seat belt retractors to bypass the buzzer/warning lights. The passenger side bucket seat also had a weight sensor and that was over ridden when you unplugged the connector in the retractor. But that was just for warning lights, 72 had no interlock. My 74 Monte Carlo had the button under the hood also. Either buckle up or snap seatlbelts and tuck in seat or behind you to start car. I don't think my 76 had an override switch if I remember correctly. Things were simpler back then.
 
My first car was a 74 Malibu that had that dreadful system. Since I always wore a seatbelt it wasn't a problem for me but when a bunch of friends piled into the car it was a hassle to get everybody buckled before trying to start up. Within a few months I found out the logic module was located under the drivers seat and popping the connector off the logic module neutered the system. The 74 models were all around wretched cars. The last of the gas gobbling pre catalyst emission controls, huge bumpers, terrible quality control.
 
I was a new mechanic in this era and got stuck doing the road calls for cars that would not turn over, sometimes more than once a day.
This and the automatic seat belts were two of the worst things ever foisted on the buying public, today it is VCM and start stop and soon alcohol testing every time you start the car. Watch the fiasco with this insanity especially with false positives due to the use of hand sanitizer.
 
Got a few questions.

3) How many 16 or 17 year old girls of that era owned a new luxury car? Or have a baby, 8:00?
I think both came courtesy of her "friend", the older guy seen dropping off his alimony payment at the post office...
 
My 74 Regal had the system and the underhood bypass switch. But what would happen is the switch in the driver's buckle would malfunction in short order so you had to either get it replaced or disable the whole system. Fortunately GM made it simple to disable, in this car there was a convenient connector right at the base of the steering column that only had to be unplugged to completely turn it all off. About a 15 second "fix".
 
I remember seeing a reference to the underhood override switch in the shop manuals for our '75 Impala, but I don't recall actually seeing the thing under the hood so I'm guessing it was short-lived.
 
I remember seeing a reference to the underhood override switch in the shop manuals for our '75 Impala, but I don't recall actually seeing the thing under the hood so I'm guessing it was short-lived.
The mandate only lasted for about a year and impacted 1974 and early 1975 vehicles.
 
I may be one of the only folks actually reactivating these on a car! My TR6 is so original and I am so OCD that I reactivated the system... I think I have a problem.
 
I may be one of the only folks actually reactivating these on a car! My TR6 is so original and I am so OCD that I reactivated the system... I think I have a problem.
Nah, not a problem. A buddy of mine replaced the talking module in his pristine '82 280ZX because he wanted everything to work I see nothing wrong with that. She's irritating, (fasten this, close that, do this, etc.) but she's supposed to be.
 
I had a couple of early 80s Ford Festiva that had the separate auto shoulder belts. I called them stranglers if you were caught unawares.
 
Back
Top