280Z fusible links

[Zed Head]

14 minutes ago, zspert said:

Using a picture of hacked up wiring as an example is hardly good evidence. Just one greasy low IQ mechanic's opinion.

There are a lot of pictures in this thread.  Can't tell which picture you mean or evidence of what.  Whose post are you responding to?

[Zed Head]

3 hours ago, Captain Obvious said:

So with that in mind... First thing that can be deduced? The 1976 color wiring diagram floating around out there is wrong.

The next thing that can be deduced is that the factory wiring diagram suffers from the same link block positioning issue that exists for 1977. If you trace the circuits and then compare them to the links on the cars, you'll see that they have the link positions wrong in the 1976 FSM. They have the blocks reversed on the FSM wiring diagram:

Basically, all of the wiring diagrams are wrong.

Here's what my 76 has.  The fusible link blocks seem to be reversed, as noted.  At least as far as wire colors.  I haven't compared the circuits, either on the car or to the other diagram in the Body Electrical chapter.

[Captain Obvious]

Thanks for that fresh pic. That's a good one to get a handle on the wire colors for 76.

Even without putting a meter on your 76, I have high confidence that your labels are correct and the link colors shown on those labels would be appropriate. If you take the two link blocks on the 76 FSM diagram and swap the two, then the FSM matches up with the car. I think they did the first screw-up in 76 and then ported that mistake in the documentation to 77 and 78 as well.

The two white wires on that front block are larger than the one side of all the other links, and that makes sense. Same as 77. Only difference is that in 77 they made the wire colors a little more straightforward and didn't do as much "color changing with splices" inside the harness. And thankful for that!

[grannyknot]

Captain O, ZH, thanks, that is one little mystery solved, it seems my car was running with no fusible link at all for the EFI.

Av8ferg, yes that seems to be the link I need too.

[Av8ferg]

So this was a great thread. Not only did it get the questions about your car addressed but it served the entire Z community. BZ (Bravo Zulu - mil jargon for nice work) to all who have been working this issue and collaborated to set the mystery straight!


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[Zed Head]

Should we start on the ZX's now?  Here's 1979.  Green is back!

[Captain Obvious]

No.     

[Captain Obvious]

So I snapped a couple more pics of the 75-77 fusible link for the EFI system. A little background... the 75-77 EFI system has it's own dedicated harness and the only connections it makes to anywhere else anywhere on the car is in one spot above the driver's knees where the EFI main relay is located. The 78 is a little different and has the EFI relays up in the engine compartment and I don't know if they use the same dedicated harness for 78.

But for 75-77 inclusive, the EFI fusible link looks like this. Green in color and includes a thick plastic strand for strain relief (that's the white part).

[grannyknot]

9 hours ago, Captain Obvious said:

But for 75-77 inclusive, the EFI fusible link looks like this. Green in color and includes a thick plastic strand for strain relief (that's the white part).

So the link that Banzai is selling is just a different colour but the same rating?

https://www.zzxdatsun.com/catWiring.php

 

Edited March 25, 2019 by grannyknot

[Captain Obvious]

Hmmmm... I have no idea.

I do know that different manufacturers are not bound to color conventions, so "green link" from one company may not be the same rating as a green link from another company. That also means the what used to be a green link from the factory on the Z could be electrically equivalent to a black link from a different manufacturer. And I have no idea where Bonzai is getting their materials from.

Here's what I DO know...

1) Pretty much all of the electrical infrastructure (connectors, contacts, etc) came from either Yazaki, or AMP. You can find one or the other of those two logos on pretty much everything.

2) The fusible link colors and cross sectional areas listed in the FSM's line up exactly with Yazaki's datasheets.

3) The new fusible links purchased from Nissan have Yazaki's name and numbers on them.

Those three facts have me convinced with a high degree of certainty that all the original links all came from Yazaki. And if that's true, then the green link is from the Yazaki FLWX series and is 0.56mm square in cross sectional area.

So... Getting to the point (there is a point...). If that black link from Bonzai is 0.56 mm square, then it should be pretty much the same as the original green Yazaki link. But I have absolutely no idea if that's the case. Maybe Bonzai would answer some questions if asked?

[Captain Obvious]

If I get a chance, I'll pull my EFI link out again and measure the OD. If all the theorization holds true, it should be about 3.0mm OD on the outside if the insulation.

On edit... Couldn't stand not knowing!

Just pulled it and checked. My green EFI link is spot on 3.0 mm (0.120 in) diameter.

Another data point to support the belief that it is a Yazaki FLWX 0.5 (0.56mm cross sectional diameter)

Edited March 25, 2019 by Captain Obvious

[rcb280z]

4 hours ago, Captain Obvious said:

Just pulled it and checked. My green EFI link is spot on 3.0 mm (0.120 in) diameter.

I checked mine as well, same diameter.