Main Relay Kill Switch - Team Integra Forums - Team Integra
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post #1 of 9 (permalink) Old 01-13-2010, 05:59 AM Thread Starter
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Got this from Club Integra.... Liked it... So I'm Posting it. Do at own risk!!!

The problem with a fuel pump kill switch is that it's very easy to bypass and run battery power directly to the fuel pump. It's easy to determine when the fuel pump isn't powered up because with the engine off you can actually hear it. Fuel pump kills are very common and widely known in part because of my write-ups several years ago but also because too many people rely solely on a cheap switch as their only security. As a result, fuel pump kills are no longer a reliable way to prevent your car from being stolen.

The idea of killing the PGM-FI relay isn't new. FCM has been describing just how to do this across many online forums for many years. However, FCM doesn't do pictorial write-ups so this has never really caught on.

The PGM-FI Main Relay controls the Fuel Injectors, the Fuel Pump, the O2 sensor, the Alternator, and the Vehicle Speed Sensor. From a thief's perspective, it's much harder to diagnose and bypass the fuel injector portion of the kill. They're going to waste too much time bypassing the fuel pump to no avail.

Tools and Parts
10mm Socket or Wrench
Flat Blade Screwdriver
Wire Strippers
Razor Knife
Angle Driver

Switch 1A or greater
18 gauge stranded wire
Ring Terminal
Butt Connector
Metal Tapping Screws

How To Kill the PGM-FI Main Relay
The Main Relay has a black, low current ground wire. If you put your switch on this one wire, you can kill the entire relay. Some of the Civic's have two wires and you will need to cut both.

This is optional but to keep the wiring stock and make this process easily reversible, I went to the junkyard and cut a main relay harness. I then de-pinned the black wire to use for my kill switch so I could tuck my original black wire away.

This is your main relay and is exactly the same for all 94-01 Integras and 92-95 Civics and Del Sols. You can remove the 10mm bolt and unplug the harness using a flat blade screwdriver.

Push the clips in on each side.

Pry the white clip up but don't completely remove it. You just need to free the black wire.

There's a little tab inside that you'll need to flatten down with a straight pick. Press on it while pulling on the wire.

Wire the Switch

once you remove the stock wire you can tuck it into the factory loom. Pin your junkyard wire and extend it to your switch. If you're not using a junkyard wire then cut your factory wire and extend the relay side to your switch. once you've decided where to mount your switch, you ground the switch's other pin using a ring terminal and a metal tapping screw or a factory bolt.

If you need a wiring diagram for a two pin switch then you have no business performing this mod. In fact, I don't know how you even feed yourself.

I wont give you an example of where to mount the switch because in the past I have found that many people are sheep and will imitate it exactly.

Relocate Main Relay

To bypass your kill switch someone only needs to ground the main relay. So you'll need to hide it. You can extend all the wires and move it somewhere but for this write-up I'm just moving it up as high in the dash as it will reach.

You need to cut the tape to separate the main relay harness from the rest of the wires in the loom.

Then I bent this tab so that the bracket would be flat.

I removed the knee bolster so I can access this spot where I re-mounted the main relay. A thief can still get to it here but if you have an alarm they shouldn't be spending enough time under the dash to find it.

This is what it looks like relocated. After you put the knee bolster and dash panel back on it's invisible when looking up from below.

Make it Work with Remote Start
If you have remote start then you'll want to wire your negative status output wire (22 gauge blue/white on DEI alarms) to the black wire before the switch.

NA!!! Still the Best!! ^_^
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post #2 of 9 (permalink) Old 01-13-2010, 08:48 AM
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Nice write up...just make sure your alarm/start brain is well hidden as well otherwise that negative status output wire is like a bypass beacon. Theres a relay writeup on here that would be another good layer on this if you have remote start
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post #3 of 9 (permalink) Old 01-13-2010, 09:21 AM
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good work and smart idea. Another killswitch idea is running it off the clutch switch. Switch is off = car thinks clutch is not pushed in and wont start, switch is on = car thinks clutch pedal is pushed in and starts. either way, adding a kill switch is a must on our cars.

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post #4 of 9 (permalink) Old 01-13-2010, 09:28 AM
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Yuck.. the install shown in the pictures is sloppy and as a result: noticeable.... no thanks.....but to each his own

While the idea is good.... grounding the wire somewhere with stock wiring is a good idea, plus using tape and loom to "hide" the wiring would make the install a LOT better/secure


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post #5 of 9 (permalink) Old 01-13-2010, 11:03 AM
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Perfect timing dude. I was thinking about doing this mod this weekend or next weekend and wanted a step-by-step DIY. Thank you.

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post #6 of 9 (permalink) Old 01-13-2010, 11:35 AM
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i actually think its a great idea.. not too many people know about this since like you said the most common kill switch is for the fuel pump... this is now Bookmarked =D
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post #7 of 9 (permalink) Old 01-13-2010, 11:45 AM
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Like Steve said, the job in this DIY is sloppily done.... and not actually how mine is done. I did have a main relay cut, and it is what solely saved my car from complete tear down. The thieves had to PUSH my car away because they couldn't start it.

Also, some have mentioned that when they do a fuel cut, their car will still run for a little bit or be able to be started for a little bit. A main relay cut does not allow for that.

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post #8 of 9 (permalink) Old 01-13-2010, 11:51 AM
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A main relay kill is an excellent idea. Just think through the process before doing any cutting etc. To make an effective install the main relay and switch need to be well hidden. As Steve/others have pointed out, the install also needs to be clean as to not draw any attention.

Be creative.

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post #9 of 9 (permalink) Old 01-14-2010, 04:26 AM Thread Starter
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Thanks Guys !! Im glad everyone found this as helpful as i did... and for it being sloppy all the wires would be added to stock loom and be well hidden!
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