Fasten seatbelt light

[emccallum]

72 240. Just wondering how the light is supposed to work. My light comes on when I start the car. Goes off when I pull the seatbelt out. If I dont buckle the seatbelt the light will come on in neutral, but go out when I shift into a gear?? That seems really wacky? Thanks.

 

[SteveJ]

I couldn't find it on the 72 wiring diagram, so I'm going to assume it was done the same was as is shown in the 73 wiring diagram.

The 12VDC+ goes to the passenger seat switch and to the driver seat belt switch. If there is a passenger (or heavy object) in the seat, the 12VDC+ goes to the passenger seat belt switch. If the belt is not latched, the 12VDC+ will go to the neutral switch. Whenever the transmission is in neutral, the 12VDC+ will go to the seat belt warning lamp.

[emccallum]

Thanks Steve! I had the 72 wiring diagram and didn't see the neutral switch line.  Pretty cool that it is still working. 

[w3wilkes]

On 2/3/2024 at 4:32 PM, emccallum said:

72 240. Just wondering how the light is supposed to work. My light comes on when I start the car. Goes off when I pull the seatbelt out. If I dont buckle the seatbelt the light will come on in neutral, but go out when I shift into a gear?? That seems really wacky? Thanks.

 

That seems odd the way yours works. In my old 73 (that went away over 30 years ago) I don't remember a seat belt light. There was a buzzer and if the seat belt wasn't latched the buzzer would buzz when in gear, but not in neutral. This seems opposite of the way you described your seat belt light working. 

[emccallum]

My have been wired differently in 73. My buzzer is disconnected, as I think there is an issue with the ignition buzzer switch. It buzzes all the time the key is in the ignition and on. No matter if the doors are closed or car is running. 

[jfa.series1]

1 hour ago, emccallum said:

My have been wired differently in 73. My buzzer is disconnected, as I think there is an issue with the ignition buzzer switch. It buzzes all the time the key is in the ignition and on. No matter if the doors are closed or car is running. 

The ignition switch buzzer is controlled by the push-button switch on the driver's side A-pillar. It's possible your switch is not operating properly - the switch closes when the door is open to complete the circuit for the buzzer and overhead light. Pop the switch from the A-pillar and check it out.

[emccallum]

4 minutes ago, jfa.series1 said:

The ignition switch buzzer is controlled by the push-button switch on the driver's side A-pillar. It's possible your switch is not operating properly - the switch closes when the door is open to complete the circuit for the buzzer and overhead light. Pop the switch from the A-pillar and check it out.

Thanks, that is a new switch and works the interior light properly.  I think to properly diagnose it, I need to review the wiring diagram and test the wires on the switch and  steering column. I just have to get motivated to lay under there. It isn't getting under the dash that is the problem, it's getting out!

 

[cgsheen1]

I have a problem with both 😒

[emccallum]

I guess it would help if I had the right wiring diagram for my year! 3/72. My seatbelt buzzer and key buzzer are the same (no key buzzer on steering column) and the buzzer is near the fuse box. The wiring diagram I have is for an early model without the seatbelt light. At least now I have a fighting chance. 

[SteveJ]

9 hours ago, emccallum said:

I guess it would help if I had the right wiring diagram for my year! 3/72. My seatbelt buzzer and key buzzer are the same (no key buzzer on steering column) and the buzzer is near the fuse box. The wiring diagram I have is for an early model without the seatbelt light. At least now I have a fighting chance. 

It is a challenge to get a static document like a wiring diagram to match production changes. The wiring diagrams we have in the FSMs were probably created before the first car rolled off the assembly line for that year. Today we are spoiled by being able to open up a CAD program and fix an error. I don't want to think about what it was like when you had to create these with vellum. 

I have seen significant differences elsewhere. In the 73 diagrams, it shows several extra wires for the intermittent wiper amplifier. That was confusing. In the 75 manual, it shows the seatbelt interlock relay that was eliminated just prior to the start of the 75 MY production. Remember that the North American 260Z had an extended production year as Nissan was preparing to roll out the 280Z. During that timeframe, the US government walked back the requirement for the seat belt interlock requirements, and I'm sure Nissan yanked that abomination out of the wiring as soon as possible.

Then there are errors that crept in, like the representation of the ignition relay for the 280Z that shows two wires going to the same place.

[emccallum]

@SteveJ I cant imagine trying to figure it out if you didnt know some of the z history. In the diagrams I see a "Step Lamp L.H. and Step Lamp RH". I guess they were some kind of other interior light for JDM? 

[SteveJ]

They were installed in Japan, but the wiring is there in your car, just like for the fog lights. I think the NOS supply of step lights was exhausted a few years back.