Electronic Kill switch?

[crokett]

This is probably being done already but...

A friend at work had his car stolen over the weekend. He'd installed an ignition kill switch but apparently didn't hide it well enough. It got me to thinking.... ignitions work (or used to) by the ignition switch in the steering column closing a bigger solenoid switch that can handle the starting amps.

Why not add some intelligence to the bigger switch such that if the car computer doesn't set a certain bit, the switch doesn't close? The computer can be controlled via key fob or a PIN punched in or something. I mean, Ford already does keyless entry via a numbered keypad on the car door. This way there is no way to bypass anything - if that bit isn't set the car never starts.

[LCHIEN]

This is probably being done already but...

A friend at work had his car stolen over the weekend. He'd installed an ignition kill switch but apparently didn't hide it well enough. It got me to thinking.... ignitions work (or used to) by the ignition switch in the steering column closing a bigger solenoid switch that can handle the starting amps.

Why not add some intelligence to the bigger switch such that if the car computer doesn't set a certain bit, the switch doesn't close? The computer can be controlled via key fob or a PIN punched in or something. I mean, Ford already does keyless entry via a numbered keypad on the car door. This way there is no way to bypass anything - if that bit isn't set the car never starts.

ultimately the starter solenoid (the big switch you refer to) is driven by two wires. Unless the computer is intrisically built into the solenoid so that the two wires driving the solenoid are inaccessible, you will always be able to jump start the starter solenoid by appling power to those two wires. Making the security computer part of the starter solenoid will probably turn a $20 solenoid into a $200 item.

However the computer that handles the security system and the engine computer apparently don't communicate. Disabling something in the engine computer would effectively keep the engine from running (since it controls fuel injection electronically, not mechanically any more). That would entail some more communication that would have to be sophisticated enough to keep it from being fooled.

[WayneJ]

Both my wifes explorer and my ranger pick up both have the chip in the ign key, this prevents engine start up without the proper key. On my ranger I also added a hiden switch for the electric fuel pump. I hav'nt done the explorer yet. Easy to install, just takes some thinking to hide it. I just added a switch in the trigger wire to the fuel pump relay.
Wayne

Edit
Most thives won't take the time to trouble why the engine don't run

[LinuxRandal]

The forementioned Ford Passlock system, can be a pain (if you work on cars). To add remote start to one of those vehicles (chip in key), you have to disassemble the steering column on some years (watch out for airbags), or in somecases you have to add another box, which fakes out the chip (voltage thing). Factory alarms, are more apt to be connected to the brain box. I had an old mechanic I worked with (heavy equipment) that had an old truck, FILLED with tools. Before you started the truck, you have to disable the secret switch, otherwise when you turned the cylinder (old style that people would screwdriver), you ran current into the gas tank.
Personally I would prefer, more of the lowjack method, because then you could disable it from a distance.

[just4funsies]

Could go a step further... On GPS equipped cars, any start other than with the proper key could activate the door locks, and the car could then drive itself to the nearest police station to deliver the thief into custody!!!

[mpc]

One idea I had years ago, have never gotten around to implementing it on any of my cars though... use a magnetic switch like those used for windows in home burgler alarms. A small reed switch can be hidden underneath the carpet someplace; a magnet wrapped in velcro then is your key. This little switch (a small glass cylinder actually) would trigger a relay; that in turn controls power to the ECU or fuel pump or whatever. Some relays even have timers on them - once picked "on" they stay ON for X minutes after power fails (Used on some Chryslers to run the engine cooling fans after you park) so you could kick the magnet off in a carjacking... the thief & his gun would be able to drive a few minutes and then get stranded away from you.

mpc

[Thom2]

The best theft deterrent that I can think of is probably the most obvious one. While I've never actually tried any of these, I've thought about several over the years ....

1.) Overhead console with map lights, use the passenger side map light to trigger a relay that controls current to the starter solenoid/relay, if the passengler side map light isn't on, the vehicle doesn't start. (can be bypassed rather easily, but not nearly as conspicuous as a toggle swith for the ignition)

2.) basically the same as above, but use a combination of events, ie wipers, parking lights and brake lights

3.) screw all the above, install a freeway blaster horn INSIDE the vehicle (no sense waking the neighbors ), like under the driver's seat. Then install a disable switch of some sort. If anybody gets in the vehicle and energizes the starter or ignition system, the door's lock and the interior horn goes off. I liked this idea the best because a.) all they want to do is get OUT of the vehicle IMMEDIATELY b.) the doors are locked impairing their escape, the longer they're in a car with a horn blowing INSIDE, the more they're gonna wanna GET OUT c.) I doubt they'll stop running until your vehicle is long outta sight

[jziegler]

I had a roommate in college that had a nice security system on his older Camaro. It had two parts. First was some kind of kill switch that he put in. Second and better was that he took the gear shifter with him when he left the car. Had it setup that it just ppped in and out. Not too easy for someone to steal the car with no shifter..

Jim

[mpc]

I've seen a similar device for steering wheels. The steering wheel pops off, then a cover plate goes over the steering column, covering the steering shaft (no vise-grip steering here!) and the plate locks. So not only do you have to hot-wire the car, you have to pick a lock to get a plate off the steering column AND THEN have a substitute steering wheel. A quick-removing shift level is a pretty slick idea.

mpc

p.s. Alarm horn inside the car... I LIKE that idea. My old college roommate was twisted enough that he'd probably want to trigger tear gas or something like that.