Wiring loom advice needed.

[brianconwy]

I am tidying up the wiring loom and there is a loose white/yellow wire. I have tried to see which pin it goes to on the ECU with a multimeter but cannot find a connection at the ECU. Also the black wire from the oil pressure switch connector at the oil cooler has broken. Should there just be one black wire. i can't see where this has broken off from.
Thanks
Brian

 

[dieseldog69]

Black wires are usually earth wires.

White/yellow could be anything.

 

[mystery]

IS IT NOT PIN 10 RED PLUG WHITE YELLOW CABLE ENGINE ECU TO( IAT) PIN 4 INLET AIR TEMPERATURE SENSOR DISCO 2 ,DON'T ASSUME BLACK WIRE ARE ALL GROUND OR EARTH WIRES WHEN AN ALARM OR IMMOBILISER IS FITTED THEY USE BLACK TO HIDE THE CIRCUIT AND ITEM IT FEEDS

 

[brianconwy]

IS IT NOT PIN 10 RED PLUG WHITE YELLOW CABLE ENGINE ECU TO( IAT) PIN 4 INLET AIR TEMPERATURE SENSOR DISCO 2 ,DON'T ASSUME BLACK WIRE ARE ALL GROUND OR EARTH WIRES WHEN AN ALARM OR IMMOBILISER IS FITTED THEY USE BLACK TO HIDE THE CIRCUIT AND ITEM IT FEEDS

I will check again tomorrow. Thanks.

 

[sierrafery]

Black wires are all earth on a D2 but the oil pressure switch's black wire is useless cos the switch is earthed via fixing ,

WY wires at the ECU as follows:
red plug :
- pin 6 - IAT(inlet air temp input part of the MAP/IAT sensor on the inlet manifold)
- pin 10 - AAP(ambient air pressure sensor on the airbox)
black plug:
- pin 15 - cruise control master switch

that's all

 

[brianconwy]

Black wires are all earth on a D2 but the oil pressure switch's black wire is useless cos the switch is earthed via fixing ,

WY wires at the ECU as follows:
red plug :
- pin 6 - IAT(inlet air temp input part of the MAP/IAT sensor on the inlet manifold)
- pin 10 - AAP(ambient air pressure sensor on the airbox)
black plug:
- pin 15 - cruise control master switch

that's all

Thanks. I have checked again today and in better sunlight with reading glasses on I discovered it is white/brown and checking with a meter it goes to this grey connector.

I have no idea where it goes from here though.

 

[sierrafery]

The WN wire through pin 1 of that connector(C0162) comes from the oil pressure switch and goes to the instrument pack for the warning

 

[brianconwy]

That sounds about right as this is the oil pressure switch plug with only the black wire which doesn't connect to anything in the socket as there is no pin. The part of the plug that connects to a pin has no wire attached. What does this pressure switch actually do? It can't have been that which helped the engine destruct can it?

 

[sierrafery]

Better rewire the switch to that WN wire cos otherwise you dont have oil pressure warning... the black wire is futile there... the switch is NC to earth and opens when there is enough oil pressure as to extinguish the oil pressure warning and if the pressure is low it closes to earth and brings on the warning... didnt you observe that there was no oil pressure warning on dash untill now ? ... who knows how much you drove it with low oil pressure eventually

 

[brianconwy]

I wasn't driving it at the time it is my wife's car. My stepson was driving it when it happened. There had been a lot of diesel getting into the sump despite changing injector seals and washers. It was cylinder one that was affected and not any of the others. I think there may be a cylinder head crack near that injector pocket. The piston ring had gone and then the piston was damaged and also the bore. The switch doesn't affect the pressure then - it just operates the warning light? Perhaps the wire got yanked when removing the gearbox in March. I will get it fixed for when I get a replacement engine. Thanks.

 

[sierrafery]

The switch doesn't affect the pressure then - it just operates the warning light?

Yes, just for warning

 

[brianconwy]

I don't think it was low oil pressure that killed the engine as when it went the camshaft seal cap popped out and there was oil everywhere.