SteveJ

When it dies, does it happen gradually or suddenly?

Now, if there are issues when the key is in ON, that's a different kettle of fish, as long as you understand it doesn't see voltage during the cranking cycle.

Which BW wire are you talking about? The BW at the switch doesn't get power until the key is in the ON position. Maybe this video will help you figure out what you're looking at. (Note: Video removed as I cannot confirm at this time that the switch operates as shown in the wiring diagrams.)

Your MOV files aren't embedding properly. You'd have better luck uploading them to YouTube and linking them that way.

Yes. Here's a link to resistance values posted by someone on Hybridz. https://forums.hybridz.org/topic/114259-oil-pressure-sender-and-gauge-specifications/

The test light isn't a definitive test. However, here's how to test the gauge:

That's what I was thinking when I looked at the 4mm rod I received today.

Brass certainly won't be brittle, and it won't melt easily. I don't know about friction, though.

All you have to do is magically contort your arms to reach behind the evaporator and use your x-ray vision to see the wires & connectors.

Don't forget about cleaning the connections on the fusible links, too. Dang, that's LOW oil pressure.

No, it was just a lack of knowledge. Dumb would have been leaving it there after you have learned about how you needed things to work. And, BTW, my suggestion about de-pinning the BW wire from the engine harness connector probably would have removed that issue, too.

Not really. That is the wire out to the solenoid. You can take the other end off the solenoid and read it again.

In the first photo, you can see the fan is blurred, so the car is running. Unless @240zadmirehad not tried to rev the engine to excite the alternator before that photo, the voltage is low. Since the alternator and battery are connected, you should see the same voltage at both. The only thing that would drop the voltage at the battery is corrosion.

The resistance on the BY wire looks low, but there's nothing indicating a short on the LR or BW wires.

Also, don't use teflon tape on the threads. If you do, you'll likely insulate the stock sender from the block.

That voltage is on the low side. It should really be reading around 14 above 2000 RPM. I suggested the cigarette lighter voltmeter because it's easy to compare it to the voltmeter in a 280Z and know what the voltage is while you're driving around.

Here are links for parts/pieces/tools that may be useful for addressing issues brought up in this thread. Verifying the voltmeter: https://www.amazon.com/dp/B01M9IKYVH Plug it into the cigarette lighter (provided it works). These things are handy to have. Verifying the oil pressure: Adapter that allows a mechanical gauge to be added: https://www.glowshiftdirect.com/1-8-bspt-male-to-1-8-27-npt-female-hex-thread-adapter/ Mechanical oil pressure gauge: https://www.amazon.com/Equus-5244-Mechanical-Pressure-Gauge/dp/B0747VR5WX Verifying the temperature: https://www.harborfreight.com/121-infrared-laser-thermometer-63985.html I haven't seen anything wrong with water temp. I'm not sure the fan clutch kicking in is a problem unless it keeps the engine too cool.

There aren't any spares on the ignition switch. The GW wire at the ballast resistor would have 12VDC+ during starting. You can back the pin out of the engine harness side of the connector to prevent shorting. Alternatively, if you need the Haltech powered while starting, do the following: In the engine bay, replace the connectors for the BW (Ignition switch one, not the coil positive one) and GW wires to a male/female insulated set and plug them into each other. Use the GW wire at the tach to run to an inline fuse and on to the Haltech. Since I have never played with the Haltech, I cannot tell you whether or not this is beneficial.

I have some ABS rod on order, too. The first materials are just to get my technique going, such as drilling out the rod for the spring. As for the lathe, I was planning on using the drill press. It's the cutting tools that I need to figure out.

I would not recommend the defroster circuit for the Haltech. It's hard for me to say anything about the GW wire since I don't have detailed photos of your engine bay to see how things are connected now. All I can say is that the way I suggested is safer because you won't have a 12VDC+ wire hanging out in your engine bay doing nothing but waiting for a short circuit to happen. (I don't like abandoned wires that could be hot.)

The harness interface in your car will have different connectors. They changed between 72 and 73. Your car will have something like this: The BW wire I suggested you find will be in the big 4 wire or 6 wire connector.

I should get some acrylic rods to experiment with tomorrow to see if I can develop some techniques with what I have on hand. I know that I encounter melted nubs when I help people with the switches.

Agreed. Assuming a linear response in the gauge, I wouldn't worry unless the needle was clearly to the right of F and staying there. As for the oil pressure, I know I've linked the parts a couple of times now for putting an adapter and mechanical pressure gauge on the engine to allow both gauges to function.

But there is an F on the temperature gauge.

I forgot to mention that my method does not leave a live BW wire in the engine bay, so that further reduces risk.