Question about 1990 Nissan 300ZX
It's actually the power wire for everything in the car. Unplug it and the car won't do anything. I wondered that also when I changed the battery, so I tried it with and without, and without the smaller black wire( smaller than the terminal wire) nothing will work. So possible it is the power for the ecu. Where the ECU is directly underneath it on the other sode of the firewall.
Hope this helped you.
Posted on Apr 22, 2009
I'm not sure what you are trying to say...
If you are saying that you have a Black Cable connected to your Positive side of your battery, then you need to check the following:
As you probably know, there should be a cable (probably black in color) with some sort of Red marking on it or a Red Rubber boot that goes to the Positive terminal on the battery (the battery should also have a + sign or a red indicator on the battery). The other Black Cable should go to the Negative side of the battery and run straight to the firewall or some metal grounding spot in the car.
Any other way will not be a good thing for the car or the ECU.
Posted on Feb 18, 2009
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