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View Full Version : The exciting black wire.



SuperMono
8th March 2009, 03:52 PM
While poking around looking for the source of coolant loss on my V6 Freebie I came across an unterminated black wire.
Fitted with a lug and looking like it belonged under a small bolt head somewhere.
Swinging in the breeze behind the L/H rear of the engine, hanging out of the loom that ends up at the injectors I think (but will confirm).

'Ahh....says I, looks like the disconnected earth wire that messes with my radio reception'
Well it is black and has an uninsulated lug, looks like most earth wires I have seen on cars.
Check the voltage to ground and that seems to confirm it is an earth, but I think starting the engine and checking the voltage with it running is a good idea.
Right up until I accidently touched the wire with the engine running and was 'excited' by a considerable voltage level, bugger if I know how high as my meter only goes to 1000VDC.
As a sparky in my previous life I have been on the tail end of a few shockos, from this experience I conclude it was a lot of volts and should not be touched.
I also conclude it should be connected to something but can't see where it ever lived (but the lug shows signes of previous connection).
For the moment I have wrapped it in the brightest red tape I have so it doesn't touch anything (which I guess might be bad) and can be found easily.
About to start looking through the RAVE wiring diagrams to see if it makes sense, otherwise I will need to go and poke my head under another V6 bonnet and see if it also has the exciting wire.

Pictures to come maybe, if I get around to it.

SuperMono
10th March 2009, 05:05 PM
Far as I can work out this is a ground wire related to the ignition coils for the rear bank. Using a combination of mirrors, small torches and 'The Force' I found an appropriate looking bolt that fixes the mounting bracket for the coils to the motor itself. This was the correct size and the only fixing back to the motor within reach of the wire.

So it is connected and doesn't seem to have done anything other than make my radio clearer on AM.

Conclusion, at some point this was disconnected and never found itself back under a bolt, but was probably touching something as the increased radio noise didn't coincide with a service.
My guess, last time the rear plugs were swapped out.

mjm295
11th March 2009, 02:09 PM
So it is connected and doesn't seem to have done anything other than make my radio clearer on AM.

Did you try touching it on your tongue first?:wasntme:Might have saved a trip to the barbers.