White / black wires - are they all grounds?

[Jesus-Ninja]

Most of them seem to be, but then I have a load left that I can no longer trace to an earthing point (slight over exuberance when first cutting stuff out... )

Is it safe to assume that anything white with a black line is going to need to be grounded?

Car is a 1998 LS400 with VVTi.

Cheers

Nick

 

[Bushwhacker]

Yes.
Some brown wires can be grounds also.

All black/yellow wires need constant 12v.
All black/orange and black/red wires need ignition 12v.

Depending on the year of manufacture, thick white and black/blue wires coming from the ECU need ignition 12v.

 

[Bushwhacker]

**EDIT** (unable to edit posts)

Make sure you have ignition 12v at the +B terminal in the diagnostics port on the engine.

 

[Jesus-Ninja]

Thanks, Vince - should make life simpler

**EDIT** (unable to edit posts)

Make sure you have ignition 12v at the +B terminal in the diagnostics port on the engine.

That's the port under the bonnet (as opposed to the OBDII port under the dash)?

 

[Bushwhacker]

That's the port under the bonnet (as opposed to the OBDII port under the dash)?

Yes. If you have ignition 12v at the +B terminal, then you should have 12v at the injectors and coils.

 

[George_R]

Start using your wiring diagram and multimeter tool, or you'll be forced to. All the color assumptions can lead to disaster soon or later.

 

[Jesus-Ninja]

Start using your wiring diagram and multimeter tool, or you'll be forced to. All the color assumptions can lead to disaster soon or later.

I am, but at the moment I have this nest of wires that I'm trying to sort out, and knowing I can cut out the white/black and re-ground them later is useful in untangling.

 

[George_R]

that's a wrong approach. Better leave just the connector alone that mates the engine loom, and wire from scratch. That's in fact easier, safer and less bulky

 

[Jesus-Ninja]

OK, so if I were to start from scratch, you recon leave the 3 ECU plugs that run through to the engine as is, and then cut off the other 3 plugs, and start wiring those 3 in from scratch? There's a separate piece of loom with, IIRC, a 26 pin plug, that runs through the bulkhead in the same place as the ECU to engine loom - wire this from scratch as well?

 

[George_R]

yes. You wire these 3 engine plugs (26, 22, 28pin) from scratch. In fact, in the absolute minimum scenario you only need the 8 following pins out of these connectors : +b1,+b,+bm,igsw,batt , rxct,txck,code . Then you power up MAF, coils, injectors, immobilizer amp and you're ready for the quick start

 

[Jesus-Ninja]

Many thanks, George.

And the separate 26 pin (big white plug with a black lever / clamp) - do I not need this?

 

[George_R]

As per above....

 

[Jesus-Ninja]

We have a runner!

http://www.youtube.com/watch?v=R_vuFNjOEeQ

Thanks for not spoon feeding me the solution, George. And thank you, Vince, for the diagrams.

My plan had been to strip back the main loom, as you know, but with a little guidance and a volt meter, I now know so much more about the engine electrics, as well as having a very tidy loom (or at least I will do!)

Thanks again for all the help.

Cheers

Nick

 

[George_R]

Congratulations!
Now wire less important stuff )) one vvti valve OCR+-, sub-o2 sensors, a/t shift lever position switch, main relay MREL /fuel pump primary relay FC