Duffy's 1/71 Series 1 240z build

[SteveJ]

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.)

 

[duffymahoney]

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. 

[SteveJ]

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.

[duffymahoney]

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

[SteveJ]

5 minutes ago, duffymahoney said:

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

I hate dealing with those.

[duffymahoney]

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

[SteveJ]

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.

[duffymahoney]

Well F.
 

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

[SteveJ]

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.

 

[duffymahoney]

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

[SteveJ]

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. 

[Blitzed]

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.