People Seeking Info

Subject More info on killing the constant power to the injectors.
Posted by DVDBURN (MD) on August 03, 2008 at 4:23 AM
  This message has been viewed 761 times.
Message I know there has already been a couple of write ups on killing the constant injector voltage. Here is a little info on how you can kill the power to the injectors and at the same time give you the ability to keep someone from starting your car by adding a kill switch.

This should probably be in the tech forum but there is also something different in the after photos of the fuseable link box that is different than in the before pics. I though it would be fun to see if anyone can guess what it is.

Getting started, here is the fuseable link box. All the way to the right is the fuse for the fuel pump, ignition coils and the injector voltage. The injector voltage is the voltage which is always applied to the injectors in the 90-94 Zs.

Here is the single smaller wire which goes to the positive terminal of the battery along side the battery's larger main positive cable. This wire has been known to break at or near the terminal and cause the Z to not start. In this picture most of the wrapping has been removed to expose the wire. You can also see where it forms into three wires as it gets close to the fuse box. The Nissan factory electrical tape is still on at the splice.

Here is the wire again but this time with the splice exposed.

Here is a picture of the fuse box flipped over and with the bottom cover removed to show where the three white wires go.

Below is the same picture except this time I have added a green, blue and red stripe to the wires so you can see more clearly which wires they are and where they go. Using the picture of the fuse box cover as a reference, the wire with the green stripe goes to a single gang terminal to the "BLUE BAT" fuse which goes to the alternator.

The wire with the blue stripe goes to a single gang terminal which provides constant power to the "LTG" fuse. The wire with the red stripe goes to a two gang terminal and provides power to two fuses. They are the "P.WDW/P.SEAT" and "FUEL PUMP/EGI/INJ" fuse. This is the wire we want to use for our voltage control to the injectors and the kill switch.

Here is the wire cut away from the three way splice. All that's needed for a kill switch and to remove the voltage from the injectors is to run two wires from a toggle switch and connect one of them to the wire which was cut from the three way splice and the other one to the splice where you cut the wire from. Instead of a toggle switch you could use a relay and control it from a switched power source. With this one wire disconnected there is no power to the injectors, coil packs, fuel pump, power windows or the power seat.

For my needs I ran two wires (orange) with in-line 30amp fuses to the three way splice for two sources of constant battery voltage and a wire (yellow) to the wire I cut away from the three way splice to be used for a kill switch.

You must run the wires under the fuse box as they originally were in order to put the bottom cover back on.

Everything back together with the wires and in-line fuses now through the harness hole and inside the fender well where the wires run to a hole which routes them to the cabin.

And one last picture of it completed. Now can anyone tell what is different? There is one main thing I'm looking for.

And lastly, here is a schematic with explaination of the kill switch function and how to use it. The schematic shows how to use the kill switch with a turbo timer. Once the turbo timer turns off the vehicle the car can not be started until the relay is latched by pressing the momentary push button. I'll place this post in the tech section in case anyone would like to vote it to FAQ. Thanks for reading!

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