Can anyone identify this?

[GregP]

Can anyone identify what this is and the purpose? 1973 240z-See photos. It's attached to the console under the dash near gas pedal. It has three prongs out the back. There is a three prong plug that may go to it, as it's just sitting there unattached for at least ten yrs. Wires are 2 black and one green. There was a dealer installed Ac that was removed and an aftermarket radio that PO had installed and butchered the wires. I have been slowly fixing them.

Edited July 24 by GregP

[SteveJ]

Year?

[GregP]

1973

[SteveJ]

I'm thinking it might be the buzzer for the seat belts. My 73 has the same device.

 

[zKars]

Parts of the fancy electric fuel pump cut off sensor wiring and relay sub harness specific to the 73. 

There is a thread on here somewhere that explains it all. 

Basically they wanted to turn the pump off in case the engine quit, so had to sense that, via alternator voltage and oil pressure? 

[SteveJ]

13 minutes ago, zKars said:

Parts of the fancy electric fuel pump cut off sensor wiring and relay sub harness specific to the 73. 

There is a thread on here somewhere that explains it all. 

Basically they wanted to turn the pump off in case the engine quit, so had to sense that, via alternator voltage and oil pressure? 

The subharness for the fuel pump that Nissan designed for the 73 when trying to solve the issue of vapor lock consisted of two 4-pin relays. The power for the coil in relay 1 came from the neutral between the VR and alternator. It is a yellow wire. The power for the coil in relay 2 was the black/yellow wire from the starter solenoid. FP relay 2 was normally closed and cut power the fuel pump during starting. These two relays were mounted on the passenger kick panel with the wiper relay, horn relay, and AC (fan) relay.

The device shown by the OP is mounted under the center console on the driver's side.

[KenFirch]

I had that connector marked as the buzzer on an old wiring harness I removed from my late 73.

 

Factory buzzer sounded kinda like this, which is why it's not connected.

 

Edited July 25 by KenFirch

[SteveJ]

15 hours ago, KenFirch said:

I had that connector marked as the buzzer on an old wiring harness I removed from my late 73.

 

Factory buzzer sounded kinda like this, which is why it's not connected.

 

That was all part of the 70s effort to annoy people into wearing seat belts. It got even worse in 74 as everybody was required to integrate seatbelt interlocks with the starter circuit. People got very perturbed that a bag of groceries in the passenger seat kept you from starting the car until the groceries were safely buckled in. You can even still see interlock in the 75 wiring diagram though the NHTSA rescinded the requirement and every automaker immediately ditched it.

[GregP]

Thanks for the replays! I guess I will keep it unattached!