The fuel pump relay kill switch (FPRK) essentially cuts power to the fuel pump.  Thereby not  allowing any fuel to be pumped into the injection system.  This is an effective theft preventer for the  Z32.

With this modification the Z32 will NOT RUN under the most common mode of theft --  cracking the steering column and hot wiring a car.

Regardless of the security system you have on your Z now, this is possible as we have read stories of Z's being stolen in this manner. It is somehow possible for the thief to bypass the starter disable feature of the stock theft deterrent system. (I'm personally looking into why this can occur.)

Essentially, whether the thief cracks the column and tries a hot-wire, or tries a compression start after doing the same; the Z will, at best, run for a few seconds and then stall as the remaining fuel in the system is quickly depleted.

This mod also makes changing fuel filters very, very easy since you will not have to open the drivers side kick panel to disable the fuel pump relay to depressurise the system.

- zippin

If you put the fuse in the back before the fuel pump, a 5A fuse ain't big enough.  It works ok if you're not accelerating hard, but if you get on the gas it'll blow.  I found out the hard way.

Hadn't really driven the Z much since I put the switch in, but I took it out for a spin last weekend.  Jumped on it from a stop light, went about 50 meters, and the car just died.  Scared the shit out of me.  Thought I'd blown an engine or something.  Came to my senses and checked the fuse.  Sure enough, it was blown.

The fuel pump will draw more current under acceleration.  You could probably put in a bigger fuse (I would guess you'd want one the same size as the fusable link), but I just took the fuse out all together.  I figure for the way I wired it - putting the switch in the power line before the fuel pump - the fusable link should provide enough protection.  I also used 20 gauge wire instead of 22 when I re-wired.

It might actually be even 18 gauge wire in the fuel pump harness, but I couldn't tell for sure.

I think the fuse should still work ok if you put the switch on the control line for the relay.  The amperage on this line shouldn't fluctuate since it's just control.

So where is it?  The relay is located behind an interior plastic panel on the driver's side below the hood release knob.  This is also where the interior fuse box is, behind a small plastic removable panel closer to the firewall, and to the left of the clutch.  This interior panel also has the dead pedal molded into it.

The shop manual also has diagrams of the relay location as well as a schematic of the relay and contacts.  The relay is probably going to be light green in color.

Second, remove the screws attaching the interior plastic panel on the left side of driver foot area. This is the panel with the fuse box and the dead pedal. I believe there are 4 to 5 screws, some hidden under the interior carpet near the firewall.  Removing this panel will take some care.  You need to bend and jiggle it to get past the hood release knob.

Now you have exposed the interior are where the relay is located.  There are plenty of other electrical components in this area so be sure of what you are tugging and pulling on.

Depending upon where you put your switch, it may be easier to cut into the wiring harness right before the fuel pump instead of at the relay. It's definitely much easier to work with the wiring at the fuel pump and the fuel pump may even be easier to get to since all you have to do is remove the center "shelf" behind the seats.

I would also advise this but please be sure to remember to disconnect the battery before you do any splicing and cutting of wires.  You should also have a good understanding of the wiring of the fuel pump so you know exactly which wires to cut.

In the picture above are several items worth oting before you start to loosen the relay. First, there is a flat aluminum stamping which is attached into the body with two screws. This piece has a slotted tang on it which the relay attaches to.  Also attached to it is a connector bar w/ a multitude of wires - don't mess with the connector!

The relay is slid over the tang, but you won't be able to remove the relay until you have loosened the screws for the aluminum stamping.  In the pic above you can see that I have totally removed one of the screws to make is easier to slide the relay off the tang. Remove/loosen the screws and slide the relay of the tang.

Second, you now should have the relay hanging loose (somewhat). Now is the time to check you have the correct relay.  Using the snap features of the relay, remove the top section.  Now try to start your Z.  If it fails to start or starts and then sputters to a stall you have located the correct relay.

Third, disconnect the battery terminals using the 10mm wrench.  If you don't do this you risk blowing a few hard to replace fuses.

Above a schematic of the actual fuel pump relay.  Lead No. 2 is the thin black wire you will be tapping into for the kill switch.

This is, by far, the most difficult part of the installation. The relay was not installed at the factory with extra wire. This makes it very difficult to get at the correct wire and have enough space to wire in the switch.  Go slow when doing this next step.

First, you want to pull on the relay to get enough of the wire exposed to do the mod.  Be careful not to pull to hard and damage the wiring or the relay connections.  You will need to expose about 1.5" of wire from the bottom of the relay connector.

Second, you will need to use a razor blade or exacto-knife or scalpel to remove the electrical tape that is holding the four wires together. BE CAREFUL not to cut any of the wires or their insulation when removing the tape.

Third, there are four wires. A thin black wire, a orange or red wire and two heavy wires that are white w/ black stripes. The thin black wire is the wire you will be splicing into.  Pull some of that wire away from the other three wires.

CAUTION:  After the next step you are at the point of no return so be careful.

After you have isolated the thin black wire it is time to cut it.  Make a cut at least 1" from the point where the wire enters the relay connector.  If you can cut farther away and still have about 1/2" of wire to the side of each cut that is good.

The object is to have 1/2" of wire on both sides of the cut, so you can remove the insulation and have enough wire to solder the switch wires into.

I assume at this point you have your switch and you have ample supply of 22 gage wire.  To begin, cut at least 4 feet of each strand of wire, you will need two strands and I suggest using two different colors (Red, Green or Black).

Why 4 feet? Because I have no idea where you intend to place your switch. And, I certainly am not going to tell you where I placed mine, although some of you already know from seeing it at E-Town.  So if you plan on wiring the switch to a remote part of the car, use more wire accordingly.

Obviously you want to put the switch in a most secret place. And place the wiring out of reach of the average crook.  I had a friend once put a starter kill switch in his map light switch.  It's a good idea, unfortunately starter kill switches, if not wired properly, do not provide protection if the thief cracks the steering column and hot wires the car.

Strip the insulation from the wire as normal. Solder the wire to the switch. There's no rocket science involved with wiring the switch.

After you have a good connection it's time to check to see if you've done everything correctly.  Make sure the exposed contacts of the switch and relay are not touching.

Re-connect the battery terminals and try to start the engine.  Either your Z starts and stutters to a stall or doesn't start at all OR it starts and runs.  Now flip the switch; your Z should do the opposite of the previous attempt.  If it does your ready to finnish.

If not, you need to backtrack and find out what steps were done incorrectly. Finnish the install by protecting the contacts (where you soldered) with electrical tape.  Replace the relay into the metal stamping tang and close up the interior panel.