One of the key things to do to get help on wiring is to identify wire colors. If you can do that, it allows me to orient things better to the diagrams in the FSM.

The unidentified 3 pin connection that only has two wire has a red wire and blue/white wire
The unidentified blue wire is solid
The not sure red wire is solid and like a 12 gauge abit thicker than the other leads.


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I was hoping you would provide information on the other connectors, too. 

FYI: There are some typical wire colors that rarely change in the 240Z. Someday I should write them up on my technical blog.

Blue is usually associated with accessory power. 

The only blue/white wires I saw in my quick look at the wiring diagram was power for the cigarette lighter coming off of the fuse box, one of the wires going from the combo switch out to the wiper motor, and one of the wires for the antenna. I doubt the wiper motor circuit would be on a connector near the blower motor. Unfortunately, the wiring diagram does not clearly identify the colors for the wires going to the radio.

I have to say that the Nissan engineers improved the layout of their drawings as the years went by. The component layout in the early S30 wiring drawings leave a lot to be desired. By the time the 260Z FSM came out, they included a lot of break-out diagrams to make diagnosing individual circuits much easier.

I would test continuity from the "no idea" wires to the pins on the other ends of the harness.  It's all right there in front of you in the big red picture, not hidden inside the dash.  They probably go to the blower or the switch and that will tell something.

 My ancient radio wiring notes mention a blue/white wire going to the antenna switch, red wire was switched power from the ignition. Presumably both going to the radio. I hope.

To two biggest questions I have on this is the blue lead off the harness by the console. Was hoping someone knew where that went. I would agree that it appears to be a accessory power. I think I may have figured out the two pin connection. I think it went to my old automatic lever.


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Not seeing the blower motor on the diagram. I could possibly figure out the wire lead if I can find that on the chart


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It is weird that Nissan doesn't seem to have created a wiring schematic for the cabin heating system.

Joe

Behind my heater/radio console i have a blue/white wire with a fuse holder labeled as a AC lead. Past the fuse holder the wire ends at a female lead. That would allow you to connect the wire you identified in the picture and because you said it was an AC car that would make some sense to me. 

Just a guess. I can send photo is needed.

46 minutes ago, Zed Head said:

It is weird that Nissan doesn't seem to have created a wiring schematic for the cabin heating system.

Yes, I find it irritating. From what I can see, the 260Z wiring diagram is the first to acknowledge that there is truly wiring in there. The 73 diagram just shows the blue wire going to the blower motor.

Joe Behind my heater/radio console i have a blue/white wire with a fuse holder labeled as a AC lead. Past the fuse holder the wire ends at a female lead. That would allow you to connect the wire you identified in the picture and because you said it was an AC car that would make some sense to me.  Just a guess. I can send photo is needed.

 

 

So found why I marked it a AC (Cooler) here a wiring diagram I used when doing my dash.

 

This a Prospero diagram

 

 

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I like the diagram.


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