Interlock Relay

[jeffdgale]

On my 74 Avanti is a fuse that is not part of the main panel but below it on the metal bracket. The diagram on the cover say "Interlock Relay" Does anyone know what a Interlock relay does, where it is? Thanks.

[Gunslinger]

For a time in the '70s...I believe only one year...the Federal government in its eternal and ongoing wisdom required all new cars be equipped with an ignition interlock. If you were in the seat and didn't connect your seatbelt, the interlock kept the car from starting. To say the least, it was not popular with the public...people would disable it or leave the seat belts connected and sit on them or whatever else it took to defeat the interlock. And that's when the interlock even worked properly to begin with. I think it was after one model year that the government relented and eliminated the requirement due to the negative response from the driving and voting public.

Try starting your car with the seat belts not connected and see if the interlock works anymore. If it no longer works, it's up to you whether to do anything about it. What it comes down to...if it doesn't bother you, don't bother it.

[Skip Lackie]

To add to Gunslinger's response:

1974 was the one year of the Federally mandated seat-belt interlock, which as he said, was rescinded the following year. Just putting a briefcase or a bag of groceries on the passenger seat without connecting the seat belt would set off a buzzer and/or disable the ignition switch. Almost everyone who bought a 1974-model car disabled the system during their first week of ownership. The easiest way of doing that was to disconnect a single-wire connector under the passenger seat. If that has already been done on your car, then you don't have to worry about the rest of the system.