deadman circut?

i know that most of the alarms out there have a "+12v when armed" wire, but has any one heard of an alarm that has +12v when diarmed"?the reason im asking is the theaves around here are good about ripping out wires and taking off before you can get your pants on, and if i could find an alarm with a "+12v when disarmed" i could rig up a "deadman switch" with the ecu or fuel pump, so that way it wont start without the alarm in working order?time is not wasted when you are wasted all the time

You can set the imobiliser circuits on many alarms to passively immobilise.

I have done something in the past that may work for your situation. Some of the newer systems that use surface mounted components will not allow this setup though. On most systems installed, not all of the wires are used. So what I do is open up the brain and locate any 2 circuits with unused wires that have either a resistor or diode just before the header pin/plug. I remove the component (resistor or diode) and solder a jumper to the holes closest to the pins (you can solder to the pins too but that doesn't look as nice). Now wire your circuit through the 2 previously unused wires. As long as the brain is attached, you have a complete circuit. If it is unplugged, you will get an open circuit. Just keep current of the circuit you want to pass through in check otherwise you are going to start burning things up. You may need to use a relay to operate some circuits, in which case you can use the pass through to ground for the relay coil and the other side of the relay coil can be hooked up to true ignition. Hopefully you can picture what I just describe. If not let me know & I'll try to come up with a diagram or example.

Go to Radio Shack and purchase this and it's mate. http://www.radioshack.com/product/index.jsp?productid=2103292

I guess I could have saved a lot of time had I read 911's post.  Same principal, but the radio shack plug will handle more current than the alarm harness.  With the current required by some of the newer fuel pumps, I would highly recommend the larger capacity plug.

i love that idea, nice and simple, its easy, and it get the job done without throwing any electronics in to go wrong. thanks man!!!!time is not wasted when you are wasted all the time