most effective kill for a manual?

Since a starter kill is basically useless in a manual transmission, what is another reliable sort of kill? I was thinking of a fuel, or ignition kill, what would be the most reliable way to make these?

LOL! Starter kill are useless anywhere - it's like cutting power to the ignition - except for newer chipped cars etc.

Short the Ignition Coil's -minus terminal to ground somewhere. That requires removal of the coil- connections and bridging to whatever ignition trigger system you have. That's much harder than adding a jumper lead, and a bridge/short to the starter solenoid.

There are immobilizer systems up here in Canada that install into a 3 point immobilizer system: starter, fuel and injector. Depending on what vehicle this is, these 3 points of immobilization will disable the vehicle from starting or getting push started.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

And Jeff we have them as well, Thatcham Cat 2 and 4 or 5 years later when the battery fails I'm asked to remove them. The point is I've never ever failed to find one and get the car going again, usually start to finish 10mins! A Mits nearly beat me the other week 'till I found there was no ignition constant and had to replace the 40amp ignition fuse in the fusebox adjacent to the battery.
Hence I'm not in favour of immobilisers, factory transponder beats all. P.S., just make one bad solder joint on the ignition or fuel line = trouble.

That's one of my arguments - when immobilisers start killing people, maybe they will rethink the whole situation!

Things like injectors can be defeated the same way as grounding ignition coils, That's good because it is pointless cutting their power.
But disabling the ECU that controls them is a different matter!   

Since starters are often accessible, it is usually pointless disabling them too.

Fuel can be a problem depending on its control. On some GM vehicles, just send 12V to the oil switch - that overrides the ECU control of the fuel pump LOL!
But again, fuel pumps should be ECU controlled (and NEVER oil-pressure controlled!).


That been the benefit of the previous generation of EFI vehicles - many options for disabling.
Modern cars are more like HDMI anti -piracy.

As to the earlier generations with carbies etc that used to cut power to the coil... poor sods!   What's the song... "Money for nothing... 'cos your (useless) chips ain't free!".


Howie knows the oldskool methods - unlike those that hacked the ignition switch trying to steal a mate's 45 year old car. Morons!
But unlike me, Howie probably knows which systems are not hackable but do NOT suffer unreliability and risk.

But anything that cuts power as a defense is usually flawed.

So I'm still not clear on what to disable that would make it all effective.

The others will have to explain what their immobilisers do.

What I am saying is to short the Ignition Coil negative to GND.
This assumes a conventional/traditional points or ignitor ignition (hence works with normal tachometers).

Because traditional ignitions are ground switching (which I often refer to as Open Collector...) - ie, the Coil+ end is connected to +12V (via the Ignition key and maybe a ballast resistor) and the coil- is connected to GND via oldskool points - else transitor or HEI etc systems - to charge the coil. The coil then fires the splugs when the GND-short opens (points open or transistor/FET/HEI turns off).

So if the coil- is never released from GND, spark never occurs at the splugs (spark plugs). Hence no engine start.
The same happens for CDIs (Capacitive Discharge Ignition) assuming they are the more common points & HEI substitute - a few types pulse the +ve to the coil instead.

In the above systems, shorting the coil- to GND will not damage the ignition system.
Prolonged connection of the coil- to GND may eventually overheat and blow the ignition coil (after say 10-15 minutes), but we are talking about an anti-theft system.


The beauty of the shorting system is that the short can be anywhere(**) and it has to be REMOVED in order to have ignition, whereas cutting power to component merely requires the jumpering of power to that component - you only have to know where the component is, not where the power is cut. (IE - a well hidden under-dash break of IGN +12V to the ignition coil - just jumper from the battery +12V to the coil+ terminal. Presto!)   

** The only limitation of the short is that is has to be close or heavy enough to short the ignition pulses. The ignition-kill switch wires on my old bike shorted the points, but were from the coil- and were too long or thin to kill the engine at hi RPM - I had a 12,000 RPM bike on top of me! Ignition kill should be coil power unless you are certain to prevent points/ignition pulsed to the coil. (The bike would never start with kill on, and kill would kill normal engine RPM - ie, to 8,000RPM. But at 12,000 RPM the magneto voltage must have been so high.....)


In summary, you have to remove a short that defeats a circuit.
You merely have to bypass anything that cuts a circuit.
For a starter motor, that bypass is called a screwdriver, or keys, etc. For other things, its low-power jumper leads; alligator clips; flying leads with spade/blade connectors etc.

How can this be accomplished with a relay? Pardon the noobness. Learning alot from you master installers though and teaching others about it.

But I'm not an installer!
You don't need a relay for a short - it need probably just be a switch, unless it's controlled by an alarm system etc.

But the relay can supply or remove the short.
The choices for that are:
- an SPST (on-off) relay that is on and shorts the points or whatever unless you disable the relay, or
- an SPDT (changeover) relay whose NC contact (Normally Closed - ie, closed when de-energised) shot <whatever> and you remove that short by energising the relay.

The former functions like an "extended switch" where the on-switch is too far for the shot - eg as per my unkillable bike on torso example. The disadvantage - the relay is normally on therefore draining the battery... (ie, its solenoid current of probably at least 50mA).

The latter makes more sense - without power, the target <whatever> is shorted. To remove the short, supply power to energise the relay and open the NC contacts thus lengthening the short (ha ha - ie, removing or un-shorting the short circuit). Since this is done with ignition on, any relay current is negligible. The risk is if the relay fails or de-energises, the short may be applied - eg, ignition is killed.   

Switches alone would be the most reliable - no need for a relay.

Actually this is all running around in circles and going nowhere. Why not just a mechanical gear shift lock? A large German Shepherd? (Works for me). ANY idea you come up with has probably been done to death before and I've probably got around it in about 5-10 mins.

Howie is not only a very clever and experienced installer etc, but also fast on the edits.
My notification clearly says ""...done to eath before... which is not only a clever ambiguous spelling error - ie, death & earth - whereby not only do those two words have certain commonality in certain primitive cultures, but are clearly a criticism of my earthing (aka grounding) technique.

However, Howie does add that HE would probably get around <any method> within 5-10 minutes. Of that I have no doubt!
But killers & immobilisers that CUT power take less than a minute.

So it depends what you are protecting against.

My system used to be the removal of the distributor rotor. Even if people knew what sort it was, would they be carrying a spare?
Nowadays I have a 2-way remote paging system. It's wired to a standard auto-destruct (as used in space ships, ocean going vessels, aircraft and automobiles should they find parasitic aliens on board or hurtle uncontrolled).


I too sense that the principle and simplicity of the method I am taking of is not understood.
By no method can be visible. The difference between a visible & invisible power cut however may be zero if standard bridging techniques are used - ie - a few seconds under the bonnet or dash. A hidden short however may take minutes or not be found (is it grounding the coil. or an ECU sensor etc under the seat?).


Howie - I shall investigate if that colorful changeling reptilian has bit-bucketed that %1000000 in its feeble divide & conquer attempt. I find it too coincidental that it was a d = 1,000,000 and not another letter that was targeted. And spelling mistakes from you are out of the question! Keep it up good buddy!


PS - by coincidence I just found mp3car: timed relay.... keeping voltage when origional connection broken...... maybe that has something?

Damn you Peter, though I edited it immediately! Actually I was going into the lounge to watch episodes 1-4 on my DVR! The Brasilian Goddess who's the lead baddie, will she EVER do a TV series that isn't Ski Fi (Firefly, Stargate etc.)? By the way, Ski Fi channel becoming SyFi?

Wot?
Was Stargate SciFi?
I thought is was a documentary - just like X-Files.

Blessed are the Ori. And to think she was born from Australia's own Farscape (meaning her SG1 mother ClaudiaBlack) with yet another SG1 commander.

Are they Lizards in this remake too?
Gotta love the references to the Mus.... . Youth though. (Too many Lerts, no Larms - but plenty of Merkans.)

That's it, Farscape was the TV series, Firefly the movie. I'll email you with how I shafted Murdoch's minions.
I was trying to remember Claudia, she was also in that wacked out series, can't remember its name but the lead actor from that series of Stargate was also in it.

Do you mean Ben Browder?

And do you mean Firefly the Series and Serenity the movie?

Enuff Wine-ing already!

Good lord you're even more anal than me!

Ah - but I got relief thanks to Lexx's sanitary system.

Besides, I looked it up.... Farscape started off.... well, it was a kiddie show. But later it had its charms....

But those oldies have nothing on the fiction & humor available these days. I wonder what today's news is?

To answer  the original question, either ignition or fuel will keep the vehicle from starting.  If you had a way to interrupt the flow of O2 into the intake, that would work too.  But the fuel or the ignition would be easier and both will work the same.  It has to have fuel and a spark to start.  Either will be just as effective as the other.

But we are into HOW.
IE - power cutting is easily defeated. That leaves ignition as that is easy to short without damage.
Same with any earthed or passive sensor that is required to run the car (which - for fuel pumps - may include oil switches in older cars before they figured the error of that!)

As Howard said, this thread is getting circular.