How To: Best DIY Immobilizer.

[oc_civic]

Best DIY Immobilizer

**Advanced Knowledge Required**

I've been bragging about wanting to this for quite some time.
I finally got around to this weekend, but I gave it a bit of a twist.

Before we start, check out this link:
http://www.autospeed.com/cms/A....html

Make sure you **read it many times** until you understand.

(civic_rice) Eric's Tweak:
I decided to scrap the starter kill Adrian Cuesta suggests, and went for the Fuel Pump kill.
I didn't exactly want to flick a switch for any of that s**t... That's kinda inconvenient... everytime you stop your car, to flick a switch.

So I messed around with the wiring so that when I remove my key from the ignition, the system disables my fuel pump.

Ingredients:

12 volt heavy duty car relay; $9.99 Radio Shack
12 volt Double Pole Double Throw (DPDT) relay; $5 Radio Shack
12 volt flashing LED; $5 Radio Shack
reed switch that closes when a magnet is nearby; $5 Ebay (Radio Shack only has 50/60mA ones.. which isn't sufficient for the circuit. I found some 1Amp ones on Ebay, and purchased mine there)
EDIT: 'WOOHOO' has informed me that his Radio Shack magnetic switch did the trick!
pushbutton that opens when pushed; (I did away with this..)
broken remote from a car alarm;
and a magnet.

Here I am, wiring all this crap up. Talk about spaghetti!

New Wiring Schematic I drew up!

Here's another one to compliment the schematic.

After you are complete, you should be safe from any thief, unless of course they carry around a pocket-full of magnets

**Note: This is a guide. I am not responsible for any damages to your vehicle due to any of it **

Please ask for permission before posting my diagrams elsewhere, or give credit where credit is due!

UPDATE 03/29/2004
Chei Sewald made a computerized schematic out of the one I drew.
Maybe this will make more sense to some!
Thanks -Cheivic-

Here's a link to my original post on honda-tech if you're interested in reading other's comments:
http://honda-tech.com/zerothread?id=791686

 

[Jay Jay]

bump to see if anyone here actually did this

 

[sohclubkid]

thats nuts... maby ill give it a try. it will be a while tho. bump for a cool fuel cutoff switch.

 

[Ls-HatchBoy]

thats actually a good idea and i know what u mean about having to flip a switch every time u get out because my rex had one and it was a pain in my ass sometimes, or im just lazy!

 

[Spray_Dat_B16]

Thats crazy and all but what if somebody has a cut key?

 

[KJMagnum]

Thats crazy and all but what if somebody has a cut key?

A cut key still wouldn't work. Those just make it easier to get in the car and possibly start it. Immobilizers prevent even the original key from starting the car if the person doesn't disable the cutoff.

 

[stolibears]

bump to see if anyone here actually did this

yes and no I couldn't get it to work. I did the one he did with the magnetic switch, but couldn't get the DPDT to keep the switch on for the fuel pump. I know it close to working, just haven't had the time to try again.

once my garage is finished, I might give it another try.

Edit: If I get it working, I'll try and make a more detailed "How To:" based on these instructions.

 

[kyle10182]

here's a quick question: what do you guys think about switching this wire:

 

[kyle10182]

can anybody get those pictures in the HOW-TO to get bigger?

EDIT: nevermind. i like this link better: http://autospeed.drive.com.au/cms/A_0059/article.html

 

[DarkCreep]

Does anyone have a link for the kill switch WITHOUT the magnet?

 

[standbackimapro]

pictures not working

 

[DonDominican]

Can Someone Make A Real Electrical Diagram From That Picture, And Show The Coils & Connections Etc...please. Maybe Im Some Type Of Stupid But I Don't Get It Like That

 

[devo1104]

Does anyone have a link for the kill switch WITHOUT the magnet?

do it the same as the magnent, only replace the magnent with a switch that won't stay on.

 

[schecter]

a bit vague, however, i would assume if you cannot connect the dots here you shouldn't be attempting this lol. i'm going to give it a shot tonight in the shop.

 

[VSP]

I threw one of these together almost two years ago and it's still working like a charm for me.

I built it on my kitchen table to ensure functionality, then took a couple of days to carefully do my own stealth install. I drilled out that little cap (that covers the bolt) in the center of our dashboards and stuck my blinking LED right in the center. I also mounted the 'arm' switch (a non-latching pushbutton) inside the coin compartment. The result was a very clean, factory-grade look. Excellent theft deterrent and very clever, simple design.

 

[shabutie88]

Hey everyone,
I just finished this install in my 95 civic about 10min ago. I figured I'd take some pics and draw some stuff up. The one I decided to build included the switch to activate, instead of automatically activating. I figured it would get annoying if I were working on my car and every time I had to start it, I had to swipe the magnet. Additionally, I made every component in the circuit easily replaceable by adding male and female connectors to everything. This can be built without soldering, I just chose to take it that extra step in case something fails.

*Supplies needed*:
1. DPDT Relay 12v
2. Automotive SPST relay 12v
3. Flashing LED 12v
4. Reed Relay (I used the .5A one from Radio shack, works fine so far)
5. N.C. Push button switch
6. A magnet
NOTE: For the magnet, I found that Radio shack sells some called Rare Earth Magnets. They're the size of a small hearing aid battery and are some of the strongest magnets.

**I strongly suggest assembling this in your kitchen or on a table somewhere prior to install, to make sure you have the proper wiring.

All right, lets get started:

DPDT Relay:
This was one of the harder parts of the install for me. At first I was confused by the schematic, I'll try to label everything as best I can. This is pretty much the "brain" of the circuit.

1. This connects to one end of your LED. Remember that LEDs are polarized, meaning they'll only work one way. The other end of the LED needs to be grounded.

2. This connects to your SPST automotive relay.

3. This wire connects to your 12v power supply. I chose to run the power directly from the battery to the relay. Mainly because many of the accessories you would get your power from, turn off when starting the car, thus no power would be supplied to the circuit.

4. This is the ground wire for the relay.

5. This also goes to your 12v power source. I chose to use a butt connector to splice the one 12v line coming from the battery into the two 12v sources I needed.

6. This connects to one end of your reed relay. You'll notice a jumper (green wire) in the picture between pin5 and pin6. This is used to supply 12v to ground when the circuit is energized.

7. This goes to one side of your N.C. Push switch.

8. This pin is not used.

SPST Automotive relay:

This part of the circuit controls the power to either the fuel pump, ignition, or whatever you chose to disable in your car. I went with the fuel pump kill. It's easy to get to and it's easy to find the right wire to control it.

1. Connects to line going to the fuel pump.

2. Connects to wire 2 from the DPDT relay.

3. Connects to line coming from fuel pump.

4. Ground.

Reed relay, LED, and N.C Push button:
For these, it should just be straight forward. Connect one end to the circuit and one end to ground. ***Keep in mind that the LED is polarized and will not work if installed backwards. The reed relay I bought from Radio shack had four pins on it. 3 on one end and one on the other. The middle pin of the 3 and the one by itself are the ones to use for this circuit.

Install:
The install is pretty much deciding where you want to hide things. I put my LED on the dash next to the interior light control, the push button down by the E-Brake handle, the DPDT relay inside the plastic housing around the e-brake handle, and the SPST automotive relay under the rear seat, and the reed relay....... well, I can't tell you where mine is, I'll leave it up to you.

If you chose to go with the fuel pump kill, here is a pic that might help:

The line you're looking for comes out of the fuel pump cover and is YELLOW with a GREEN stripe.
1 in the picture is the wire coming from the car and 3 is going to the fuel pump (these numbers match up to the SPST diagram from earlier).



FUNCTION:
The way the circuit should work is as follows: With the car turned off, the LED will be on. This will let you know that the fuel pump is off and the circuit is working. To start your car, swipe the magnet at you secret location to activate the reed relay. Once the reed relay is activated, the LED should go out and the car should be able to start. Once you're back from your trip to McD's for a delicious McRib, turn off the car. The immobilizer circuit won't activate by itself. To activate, press the N.C. push button. This will turn off the fuel pump and turn on the LED. If you press the button while driving, or someone else does, it will cut off the fuel pump. That said, don't install the push button where someone could press it by accident.

If anyone has any question, or noticed I missed something, send me a PM or something. Have fun with this one!!

 

[shabutie88]

Hey everyone,
I just finished this install in my 95 civic about 10min ago. I figured I'd take some pics and draw some stuff up. The one I decided to build included the switch to activate, instead of automatically activating. I figured it would get annoying if I were working on my car and every time I had to start it, I had to swipe the magnet. Additionally, I made every component in the circuit easily replaceable by adding male and female connectors to everything. This can be built without soldering, I just chose to take it that extra step in case something fails.

*Supplies needed*:
1. DPDT Relay 12v
2. Automotive SPST relay 12v
3. Flashing LED 12v
4. Reed Relay (I used the .5A one from Radio shack, works fine so far)
5. N.C. Push button switch
6. A magnet
NOTE: For the magnet, I found that Radio shack sells some called Rare Earth Magnets. They're the size of a small hearing aid battery and are some of the strongest magnets.

**I strongly suggest assembling this in your kitchen or on a table somewhere prior to install, to make sure you have the proper wiring.

All right, lets get started:

DPDT Relay:
This was one of the harder parts of the install for me. At first I was confused by the schematic, I'll try to label everything as best I can. This is pretty much the "brain" of the circuit.

1. This connects to one end of your LED. Remember that LEDs are polarized, meaning they'll only work one way. The other end of the LED needs to be grounded.

2. This connects to your SPST automotive relay.

3. This wire connects to your 12v power supply. I chose to run the power directly from the battery to the relay. Mainly because many of the accessories you would get your power from, turn off when starting the car, thus no power would be supplied to the circuit.

4. This is the ground wire for the relay.

5. This also goes to your 12v power source. I chose to use a butt connector to splice the one 12v line coming from the battery into the two 12v sources I needed.

6. This connects to one end of your reed relay. You'll notice a jumper (green wire) in the picture between pin5 and pin6. This is used to supply 12v to ground when the circuit is energized.

7. This goes to one side of your N.C. Push switch.

8. This pin is not used.

SPST Automotive relay:

This part of the circuit controls the power to either the fuel pump, ignition, or whatever you chose to disable in your car. I went with the fuel pump kill. It's easy to get to and it's easy to find the right wire to control it.

1. Connects to line going to the fuel pump.

2. Connects to wire 2 from the DPDT relay.

3. Connects to line coming from fuel pump.

4. Ground.

Reed relay, LED, and N.C Push button:
For these, it should just be straight forward. Connect one end to the circuit and one end to ground. ***Keep in mind that the LED is polarized and will not work if installed backwards. The reed relay I bought from Radio shack had four pins on it. 3 on one end and one on the other. The middle pin of the 3 and the one by itself are the ones to use for this circuit.

Install:
The install is pretty much deciding where you want to hide things. I put my LED on the dash next to the interior light control, the push button down by the E-Brake handle, the DPDT relay inside the plastic housing around the e-brake handle, and the SPST automotive relay under the rear seat, and the reed relay....... well, I can't tell you where mine is, I'll leave it up to you.

If you chose to go with the fuel pump kill, here is a pic that might help:

The line you're looking for comes out of the fuel pump cover and is YELLOW with a GREEN stripe.
1 in the picture is the wire coming from the car and 3 is going to the fuel pump (these numbers match up to the SPST diagram from earlier).



FUNCTION:
The way the circuit should work is as follows: With the car turned off, the LED will be on. This will let you know that the fuel pump is off and the circuit is working. To start your car, swipe the magnet at you secret location to activate the reed relay. Once the reed relay is activated, the LED should go out and the car should be able to start. Once you're back from your trip to McD's for a delicious McRib, turn off the car. The immobilizer circuit won't activate by itself. To activate, press the N.C. push button. This will turn off the fuel pump and turn on the LED. If you press the button while driving, or someone else does, it will cut off the fuel pump. That said, don't install the push button where someone could press it by accident.

If anyone has any question, or noticed I missed something, send me a PM or something. Have fun and take your time!

 

[See-Tee-R]

I made a diagram according to the relays I bought at radioshack. Someone please double check for me to make sure everything seems correct, as Im not 100% sure it works. *Im building it right now*

 

[shabutie88]

I checked it, looks good to go.

 

[pinoiballa14]

ok i get most of this. do you leave the magnet on the reed relay or do you simply jsut swipe it? and where do you connect your grounds? and you ahve to connect 2 wires to the battery. do you connect them like you are connecting hids?