needed: security system on 240z

This should do it.......

palladin said:

I had posted a schematic for a kill switch. If you have points and not Elec Ign, you can just run a hidden switch to the cold side of the coil, thus not allowing it to start. As with any switch, you must be able to outwit any potential thief. Given time and half a brain, perhaps a thief could figure out you were grounding the coil unless you tapped into the grounding wire up the line. This would be the easiest method. You could also put an interrupt on the solenoid wire but you could still push start it.

Sadly, if someone really wants your car to sell to Saudi Arabia, it's gone and there is not much you can do. You can discourage the locals. and of course you can always take the rotor button with you.

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Here is your schematic: http://www.zcar.com/dlattach/attach,1324/70-83_tech_discussion_forum/kill_switch_894873.0.html

I am trying to follow what you are talking about and I get that you have both a switch and a relay. It seems the relay is powered, and so the coil ground is open, when the key is on and the switch is closed. When powered off or if the switch is open, the relay is NOT powered and so the coil ground is closed - the car will run. Is this right?

So the wiring...is this the wiring of a 1970 240z? You talk about headlight washer circuit and mirror switch circuits and I am unsure if a 240z has these circuits.

You have the switch somewhere around the driver's seat and it seems you are sending 12v from the mirror switch power wire, which is live with the ignition switch on, through the kill switch and into the lime green plug/green w/blk stripe wire in the driver knee panel. This powers the headlight washer circuit to green w/blk stripe wire by the coil. Alternatively, you say the 12v kill switch circuit power can come from the ignition switch itself or the cigarette lighter.

Therefore, you must have the relay located by the OEM wiring by the coil. So you mention 4 wires to the relay, but you point out 5 connectors. Your #4 wire goes to the bottom horizontal connector and your comment about the top horizontal connector: the bottom horizontal connector is closed when the relay is NOT powered and the top horizontal connector is open when the relay is NOT powered. Since you want it open only if the relay is powered by ignition on and kill switch thrown, you use the bottom horizontal connector.

So there are two circuits in the relay: the switch circuit and the coil ground circuit.

switch circuit: you used the green w/blk stripe headlight washer wire, which now has the kill switch powering it to relay #1. Does this mean the black wire from the headlight washer circuit is your ground at relay #2?

coil ground circuit: I got confused about what you said with the black w/white stripe wire from the coil ground. You taped it up and ran a new ground? Why didn't you just use the coil ground wire to relay #3? And so relay #4 is a new wire to the neg coil terminal.

Is it the case that the kill switch always turns on when you turn the car off, so you always have to unkill the switch to start the car? Or do you need to remember to close it, to protect the car?

More broadly speaking, comparing this solution with a remote access solution (Crime Stoppers or Viper), those have many features: door lock/unlock, remote start, engine disable, dual stage shock sensor - which is evidently for whether your parked car gets bumped or broken into. I am up for electronic locks (even power windows). Remote start is a pipe dream without the choke, I think. The thing I am having trouble determining is what kind of engine disable it is. The Viper has a Failsafe® Starter Kill, and I cannot tell for the CrimeStoppers kit. Does this mean it does NOT break the coil circuit, but just the starter circuit, and so a push start will do? Perhaps with all the other stuff, it is well enough protected but I do not know enough to say for sure.

palladin said:

Not to diss Crimestoppers...but there is the problem of false alarms. Also, how many times have you heard an alarm and no one investigated. So if you got one, get one that sends a signal to your remote.

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Yeah, that's for sure. People, myself included, just tend to get annoyed that the loud noise is interrupting the "Game of Thrones" episode I am trying to watch. These aftermarket alarm systems seem to be especially annoying. A silent alarm/remote indicator seems like the best approach, although I would imagine a load alarm would scare off all but the most proficient and determined, even if no-one came to investigate. Most likely it shortens the time a thief would want to spend troubleshooting an engine kill switch.

Auto door locks (and power windows) are interesting additions. In particular, removing the internal hardware for the existing manual locks, and replacing with auto-locks, would prevent them getting into the car with those flat pry-bar thingies (can't recall the name of them).

Steve240Z73 said:

Both of my Z cars have electronic ignitions. Both have rotors.

Have you opened your distributor cap and looked inside? If you pull the rotor, I doubt a thief will have a replacement handy.

IMHO, Palladin has the easy answer.

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I have not received my car yet from the seller, so all I know is he replaced the stock distributor with an electronic distributor. I have no idea if this still has a rotor.

I am not excited about the prospect of protecting my car each time I park by pulling the rotor.

"...Would your schematic cover putting a switch on the cold side of the coil with Elec Ign?..."
Basically it defaults to the connected position so if the relay was to crap out on you, it would be closed and thus your coil would be grounded. When you throw your switch, you are applying ground to the relay which activates it when the key is turned and power is supplied. Thus no drain on the battery. note: back in the day, you hot wired a car by running 12v to the hot side of the coil. The cold side (neg) was supplied by the opening and closing of the points.

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Regarding that back in the day: it sounds like this is no longer the case? The coil is grounded with a wire and not with the points?

I have the perhaps mistaken conclusion that you have to throw the kill switch, when you park, to protect the car. Is this the case?

Ideally, I would like to be driving with the kill switch "off", so the relay unthrown and "naturally closed" and the coil firing. Then, when I park, turn off the car and have the kill switch "thrown" by default. This way when I, or a bad guy, gets in the car and tries to start it, the kill switch is "naturally closed" when the ignition is powered, the coil relay is thrown, coil cold circuit broken and the car won't start. I would have to throw the kill switch to start the car. I would like to not have to flip a switch when I park and turn off the car.

Perhaps having a push button switch, instead of a toggle, is the approach I am thinking of. It defaults to coil circuit open on ignition circuit powered. Punch the push button to close the coil circuit and run. Punch the button again to kill it for car-jackings. If the relay goes bad, then what?

Sorry to completely complicate such a simple solution.

thanks,
Rob

I wonder how likely a circuit failure is. I would not think that likely, so it should be acceptable to have a N.O. engine circuit.

Here are two links to the same circuit, that uses a magnetic reed switch to enable the starter/coil circuit, a push-button to disable the circuit, for car jackings, and two relays, one normal SPST Bosch relay, and a latching DPDT relay. The only change I would make is to power the DPDT latch relay with the ignition power rather than constant 12v battery power, so when the car is off, it automatically arms.

http://cod.homelinux.org/C/saab/mag_immobiliser/magnetic_immobiliser.pdf
http://www.automotiverewire.com/Documents/ImmobilzerWiring.pdf

• 
  [li]Engine circuit to the N.O. terminal on the Bosch SPST relay - disabled by default.[/li]
  [li]SPST relay coil circuit to the N.O. circuit of the DPDR latch relay - disabled by default.[/li]
  [li]Ignition power to the DPST relay coil, but reed switch on the ground side - disabled by default. Closed Reed switch activates DPDT.[/li]
  [li]Swipe the magnet over the reed switch and the DPDT powers the SPST relay coil and turns the engine circuit on. Start the engine and go.[/li]
  [li]Push the push-button and depowers the DPDT relay and thus depowers the SPST relay and breaks the engine circuit. Engine stops for car-jacking.[/li]
  [li]Turn off the ignition when stopped and the DPDT loses power and resets the default disabled engine circuit.[/li]

lojack is definitely a possibility, although $700 is steep. At least it is a one-time charge. I will consider this.

palladin said:

*******! I looked all over and never found one...I was ready to steal one off someone's window but couldn't find those either LOL

Now...where are you going to mount it?

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I did a LOT of searching yesterday but was just finding the house window circuit type for a long while. I just now searched on 'reed switch' and digi-key popped up. go figure.

I realize that those instructions call for using a used remote fob and placing a battery in it. However, if I use the ignition circuit to power me, then I will have to turn the key in the ignition, then swipe the magnet in my fob...which is on my keychain...****! I recall my 71 240z allowed me to remove my key while it was running.

So, either I use constant battery to power the kill circuit or I leave my swipe battery off my keychain.

Or I buy a delay timer: http://www.tessco.com/products/displayProductInfo.do?sku=312752&eventPage=1 with constant battery to power my kill circuit. Then I turn on the ignition, turnoff the ignition, swipe the fob magnet, restart the ignition and start the car. Ugh! Of course, this allows me to restart the car after a stall, without swiping the magnet.

I will have to think about this more.

I was thinking about placing the reed switch 2 cm left of the ... naw, I'm not telling!