1 minute ago, duffymahoney said:

You lost me on that. 
 

But I found my first melted wire. Off the ignition. The black and white, looks to be the ACC circuit. I can smell the burnt wire as well  

I told you to disconnect the engine harness from the dash harness and re-test. If you test the engine harness and find no short, you can suspect the short is in the dash harness. 

That black/white certainly got overheated. You are quite possibly correct that it is on the ignition circuit branch out to the ballast resistor. You can verify that, but it takes using a multimeter with long leads. By the way, this can be handy for that purpose: https://www.harborfreight.com/electrical/electrician-s-tools/30-ft-retractable-test-leads-58024.html (Note, they are only designed for low current applications.)

 

I am worried about both the B/W and the W/R wiring. 

 

I can't seem to find a way to disconnect the engine harness from the dash, the schematic seems to show a plug, but I cannot find it.  Googling now. 

16 minutes ago, duffymahoney said:

I am worried about both the B/W and the W/R wiring. 

 

I can't seem to find a way to disconnect the engine harness from the dash, the schematic seems to show a plug, but I cannot find it.  Googling now. 

Have you looked in the passenger footwell area? If you have a big aftermarket evaporator, it blocks you from easy access.

5 minutes ago, SteveJ said:

Have you looked in the passenger footwell area? If you have a big aftermarket evaporator, it blocks you from easy access.

I have dealer installed AC.  So it's behind that beast! Darn

5 minutes ago, duffymahoney said:

I have dealer installed AC.  So it's behind that beast! Darn

I hate dealing with those.

The ignition  B/W and the W/R seem to be fused. Or am I reading that wrong?

Those wires feed fuses, but technically, there is no fuse from the alternator to the ignition coil positive. The wiring diagram shows a fusible link at the alternator, but I don't recall ever seeing that in the wild on a 240Z.  I could have used one there 27 years ago.

Well F.
 

B/W, R/W, B/R and B/Y all tone your ground on my ignition 

Get resistance readings, not tone. I think I have mentioned in one of my YouTube videos that you can get a "false positive" with a tone.

Also please be more descriptive with your measurement techniques and testing procedures. Where you put your probes is important. 

Here's an example, for the B/Y wire, it goes through the solenoid and on to ground. If the wire is connected at the solenoid, you could read the resistance of the wire in the solenoid when doing a measurement. Depending upon how your meter is set up, that may set off the tone.

If you're not too experienced with multimeters, these videos may help.

 

I was putting a positive lead into the ignition plug and getting a tone on each of those wires.  

9 minutes ago, duffymahoney said:

I was putting a positive lead into the ignition plug and getting a tone on each of those wires.  

What meter are you using? Does it only have one lead? Take photos of your testing setup and don't skimp on details. 

Duffy,

Don't want to complicate all the info you're receiving. Your in need of a 12v switched lead? Your running a Haltech Elite 750 that has a 34 pin main connector on top of the ECU, you must have a 34 pin harness connector? correct, Pin 26, looking at the connector on the top of the ECU, lower left corner, 12 v switched connection for multiple components.