Kill Switch for 5th gen (92-95) Civics

[ajohnmeyer]

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!

[GasSavers_TomO]

Nice DIY! No if you put the switch in an inconspicuous place, it can act as a security switch as well.

[ajohnmeyer]

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.

[SVOboy]

Man, I didn't see this post at first, nice job,

[joy123]

sorry for my ignorance, what exactly a kill switch does?? and how could it effect mpg!!

[GeneW]

Originally Posted by ajohnmeyer

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.

This kill switch "duplicates" the "solder cracks" issue that causes the infamous "main relay problem" in those series of cars. Nice security touch as your average car thief won't know where to go next. They'll either flat bed or rip off what they can take and leave.

Gene

[dogncatboy]

Killer security mod. Did mine in under an hour. Thanks for the excellent post.

[steve0701]

Great article, but by 2002 the Civic's FI fuse was relocated to the main fuse box under the hood. Has anyone discovered a good way to route wires into the passenger compartment?

[sonyhome]

So these are 2 kill switch methods:

1- Cut the fuel injection or the ECU (?)
2- Cut the fuel pump.

Can you really use that to P&G with a civic without side effects like:

- loosing power brakes or power steering (and if so does it matter when driving say 30MPH)
- resetting or causing an error in the ECU forcing it in open loop, or some bad state

And how easy is it to restart the engine with both methods? Just go in gear?

Has anyone experienced how damaging for the car it is to use the starter too often when turning off the engine at red lights? And what wear does it take? Only the carbon contacts to replace or full starter replacement?

BTW, for the Del Sol the fuel cut-off might be a little different. Wire might not run there...

The EFI method would likely work also for the older Acura Integras since it sports very similar parts to the civic.

[theholycow]

Originally Posted by sonyhome

So these are 2 kill switch methods:

1- Cut the fuel injection or the ECU (?)
2- Cut the fuel pump.

3- Cut ignition, same as turning key back except it's more ergonomic and you can wire it to ONLY the ignition wire, not the accessory too.

Cutting the fuel pump would be the easiest one but it may take a few seconds to die as the car continues running on pressure already in the fuel lines.

Can you really use that to P&G with a civic without side effects like:

- loosing power brakes or power steering (and if so does it matter when driving say 30MPH)

Power brakes remain working for two to five applications after the engine is off. Then the brakes still work but you need to have a strong leg (and they're difficult to modulate). However, you should never get to that point; if you did, then you failed as a driver to make good decisions and anticipate needs. EOC is the low priority, with safety being well worth investing a small amount of gas (just long enough to restart the engine for a couple seconds).

Power steering is probably not an issue in most vehicles. Modern vehicles with speed sensitive steering almost entirely turn it off at speed, and most vehicles since the '90s don't give you much power assist anyway, opting for "more feel" and "sporty" steering. That said, I don't have much EOC experience outside of my VW, which has electric power steering that seems to stay running even when the engine is not. I've done short EOCs in my truck and can feel the difference but can still steer fine; years ago I've done short EOCs in a Pontiac and a Cadillac, and again, I was able to steer well enough.

- resetting or causing an error in the ECU forcing it in open loop, or some bad state

This varies from car to car, and is probably the most important part of choosing how to kill your engine. Barbarically cutting power to the fuel injectors may throw a code on some vehicles. Cutting power to the fuel pump will almost certainly throw a code.

And how easy is it to restart the engine with both methods? Just go in gear?

Bump starting is actually very easy and smooth (and fun the first time you do it at speed). See this quote from PaleMelanesian:

Originally Posted by PaleMelanesian

I bump-start any time unless I'm actually stopped. A quick up-down pulse in 5th to fire the engine, then choose the gear and let it out again. There's little-to-no jolt or momentum lost that way.

Indeed, it doesn't even take much practice to get it right. You don't have to fully engage the clutch; just bring the pedal up part of the way, you see the tach jump but don't feel the car buck. I bump start in 5th gear all the way down to ~12mph, though it's not quite dependable unless I'm above 15mph.

Has anyone experienced how damaging for the car it is to use the starter too often when turning off the engine at red lights? And what wear does it take? Only the carbon contacts to replace or full starter replacement?

I read a post about it a month or two ago, but I'm not sure what would be good search terms to find it again. The poster made a pretty good case for it not being a problem.