Kill switch for 88-95 Honda Civic/CRX/DelSol

[AndrewJ]

*thought it was about time to drag this over from GS*

So I just installed a kill switch in my CX and I thought I'd share the info with all my fellow Civic owners so that you will not have to obsess over wiring diagrams all afternoon like I did.

This How-To (for the "basic" kill switch) will work for all 5th generation Honda Civics and DelSols (1992-1995) that have airbags (SRS).
Difficulty level **
Advantages: fast engine kill, easily removable (you'll never know it was there).
Disadvantages: also kills the speedometer/odometer while the switch is off.

First, let's list the parts that you will need:
-Inline ATC style fuse holder
-Interrupter switch (simple rocker switch sold at an auto parts store)
-Male spade connectors (2)
-Female spade connectors (2-3)
-Butt Splice connector (1)
-Round or forked terminal (optional)
-5' of 16-14awg wire




First I'd recommend you find some place that you'd like to put your switch in. The easiest thing to do is to find a blank accessory panel in your dash and install the switch in there. Just gently pry one out with a small screwdriver.




Next you need to open the fuse panel under the dash, and locate the 15 amp fuse that supplies the switched power to the PGM-FI main relay. Pull out this fuse. Now try to start your car. If it cranks but won't start, you pulled the right fuse. Congrats.




Now you have to put together the wires that will run between the fuse box and the switch.

-The first piece will be about 2' piece of wire with a male spade on one end and a female spade on the other. (shown at top of photo)

-The second piece will start with the ATC fuse holder, but a male spade on one end, and the butt splice on the other. The butt splice will connect to one end of an approximately 1' length of wire (depending on where your switch is placed), with a female spade on the other end. (shown in middle of photo)

-The third piece is optional and only applies if you have a lighted switch, a lighted switch requires a ground wire, so you need a piece of wire about 2' long with a female spade on one end and a round or forked terminal on the other. (shown at bottom of photo, coiled)




Now you'll need to cut a hole to mount your switch in.





Now put your wires through the hole you've made, and hook them up to the switch the first wire will go to the terminal marked "switched" (or something like that, markings will vary among manufacturers)
The second wire (with the fuse) will go on the terminal marked "power"
and the final ground wire will go on the terminal marked "ground" (if you have one)




Now, put that 15 amp fuse that you pulled out of your fuse block into the inline fuse holder in the second wire. Now plug in the two male spades in the first and second wires into the place in the fuse block where the 15 amp fuse came from. If you have a ground wire, just find a bolt or screw that goes into a metal panel or firewall, loosen it, and slide the terminal of the ground wire underneath. Re-tighten the bolt and you're done.



Enjoy your kill switch!

[SVOboy]

Nice! I don't think I ever saw this,

[AndrewJ]

The "Advanced" kill switch will work for any 88-95 Civic/CRX/DelSol.
Difficulty level ***

Advantages: speedometer/odometer function, works on more cars.

Disadvantages: takes longer to kill the engine (startup is still very quick though).
This version is only slightly more difficult than the "basic" switch.
It does not have the instantaneous "kill" of the basic switch, but the speedometer/odometer is unaffected.

Parts List:
-Interruptor Switch
-Two lengths (about 2') of 16-14awg wire
-Female spade connectors (4)
-Male spade connectors (2)
-Heat shrink tubing (preferred) or electrical tape.

Mounting the switch remains the same. The only difference is in the wiring under the dash.
This time we will begin by prying up the drivers side scuff plate.




Now look just under the carpet, there should be a long skinny black plastic conduit box. If you pry open the conduit you should see a plethora of multi-colored wires.




If you have a 92-95 Civic you'll be looking for the only yellow wire with a green stripe on it, it should also have small silver dots. This wire will henceforth be known as the fuel pump wire For all of you 88-91 Civic folks, you're looking for the yellow wire with a black stripe (may also have dots) This too will henceforth be known as the fuel pump wire Separate the fuel pump wire from the rest and cut it about 1/3 of the way from the front (firewall) side of the conduit.




Now you'll need to put a female spade connector on one end of the fuel pump wire (seen above) and a male spade connector on the other end of the fuel pump wire (seen below)



In preparing the wires that run to the switch, attach a female spade connector to one end of both wires, attach these connectors to your switch. On the other end of the wires, attach a male spade connector to one, and a female spade connector to the other.




Attach the switch wire with the male connector to the female connector of the fuel pump wire, and the female connector of the switch wire to the male end of the fuel pump wire. I highly suggest that you cover all of the exposed metal of the connectors with electrical tape or preferably heat shrink tubing. This will prevent the connector from accidentally shorting out your fuel pump.

[bennelson]

I also found a kill switch mod on Instructables.

Seems pretty straight-forward.

I was thinking both a start and kill button on my stick shifter would be pretty cool.

[brucepick]

Has someone done a kill switch for a Gen 6 Civic, that is, '96 - '00?

[Clev]

I like the "Advanced" switch better--not only because it keeps the odo running, but killing the PGM-FI means killing the computer, and that's an expensive bit to switch on and off a dozen times a day.

[Christ]

Check the wiring on your main relay... I can't remember the pinouts right now, but you can put a switch on one of the pins to ground it, and it will shut down the fuel pump.

You could also put a switch inline with your ignition system, which will instantly kill the engine without killing the speedo and odo.

[some_other_dave]

You can also interrupt the power supply to the fuel injectors, which is what I plan to do. Eventually...

-soD

[Christ]

Whatever happens, I prefer to also cut the power to the coil/ignition system. I've been told that since the coil/ignitor setup is essentially a capacitor, that it shouldn't be left with power when it's not discharging.

I don't know if it's true or not, I never bothered to research it, because it happens to fit into my cutoff switch plan anyway, but every time I've made a cutoff switch for anything, that has been the primary thought.

Other than that, I don't like cutting fuel first, as this can put you in a lean situation (especially a fuel-cut rev limiter).

And if you cut ignition first, without cutting the fuel pump, you're still pumping fuel through the engine until it stops... so you're flooding the engine, putting fuel into your oil, and polluting that much more... which is why I decided to make a fuel/ignition cutoff instead of one or the other...

I'm thinking it would be easier to cut my injectors though, since they share a common signal with a switched (at the ECU) ground.

I could put the switch on the signal... but as soon as I hit it, I'd end up with a code 16 in my ECU (Injector(s)) That wouldn't reset unless I put a ECU reset switch in my car... (My car's reset procedure is "pull the hazard fuse" but you can just switch it so that it grounds momentarily)

[Clev]

Originally Posted by Christ

Whatever happens, I prefer to also cut the power to the coil/ignition system. I've been told that since the coil/ignitor setup is essentially a capacitor, that it shouldn't be left with power when it's not discharging.

I don't know if it's true or not, I never bothered to research it, because it happens to fit into my cutoff switch plan anyway, but every time I've made a cutoff switch for anything, that has been the primary thought.

Other than that, I don't like cutting fuel first, as this can put you in a lean situation (especially a fuel-cut rev limiter).

And if you cut ignition first, without cutting the fuel pump, you're still pumping fuel through the engine until it stops... so you're flooding the engine, putting fuel into your oil, and polluting that much more... which is why I decided to make a fuel/ignition cutoff instead of one or the other...

I'm thinking it would be easier to cut my injectors though, since they share a common signal with a switched (at the ECU) ground.

I could put the switch on the signal... but as soon as I hit it, I'd end up with a code 16 in my ECU (Injector(s)) That wouldn't reset unless I put a ECU reset switch in my car... (My car's reset procedure is "pull the hazard fuse" but you can just switch it so that it grounds momentarily)

Interesting. Does doing an 'ECU reset' actually disconnect and reconnect power, or does it signal the ECU to do a warmboot? I don't have a camshaft sensor in my Accord, so ideally I'd like to disable the injectors, but I'm trying to avoid powering the ECU on and off, since it's one of the more expensive bits in the car to replace.