I am going through and terminating my flying lead harness and came across a couple questions...

There are are 4 or 5 GY/R wires in the wiring diagram that aren't on the main connector and are labeled "Sensor supply via 10A fuse"...What are these wires for? I could only find one or two in the harness and it looks like the previous owner never used them as they are completely covered in shrink wrap.

Also, how can I tell if the CAS and serial cable shielding wires are grounded correctly?

Thanks!

 

Did you figure it out? There is one specifically that is GY/V? On the main fat harness.

Grey Yielded / Violet? (or Purple)


Me and a buddy were labeling everthing last night and were stuck on those few Grey yielded wires.

 

"GY/R"...(gray with red stripe), i see 4 of them on the diagram...

 

The grey/red wires are supplied switched 12v wires. You should have one with your INJ outputs, and sensors... others can be used with PWM's where required, all coming off of the fuse block 10a Fuse.

The Yellow/Red wire is the 12v source for your IGN outputs, aswell. Also from the fuse block.

 

i am going to use an efan with one of the pwm outputs and that should be it. is that the only one i need to terminate then? the previous owner had a very similar set up and it doesn't look like he was using that wire.

 

I would personally recommend running your efan off of a separate power source, through a relay with the adequate amperage.

Something like this:

RELAY COIL:

PWM output(pulls to ground)
Grey/Red 12v source

RELAY LOAD TERMINALS:

Fused 12v from battery
12v(when relay closes) to fans

 

that's what i was planning on doing...i just wasn't sure if i needed that grey/red wire or not. looks like i do, thanks a lot.

 

No prob.

Good luck.

 

Im sorry. The wire i was refering to is Grey Yielded. The wire inside is violet.
Any knowledge as to what is it?

 

Shielded grey?

That would be your O2 sensor input.

 

Factory o2 sensor? or wideband?

 

It would be for the narrow band O2, which if you're running a stand alone, isn't really all that necessary.

Wideband O2 can be wired to any of your Aux. Inputs, and more easily wired to your Spare A/D 2 which is already plugged in the harness.

 

Used to power external sensors (switched power - most 3 wire sensors) -such as fuel pressure sensor, WB, Oil pressure, etc

A simple resistance check can tell if you shielding is grounded properly.

 

Make sure what power your sensor uses though, a lot are actually 5V.

 

can you elaborate?

 

use an ohm meter. check how many ohms you get between the ground and the sensor sheilding? i think thats how its done.

 

Correct, it may be to the 0V instead of ground though depending on ECU/wiring, so check that instead if no circuit to ground.

 

Yes alot are 5V (if you buy an after market one they should give you graph to calibrate it).

 

Correct -

If you measure the sheild to a grounded point and you get very low resistance your cable is grounded somewhere (could be on purporse or a short).