Stealth FCO idea.
 

The other day I am driving my Ranger, using my ignition key EOC method and I got to thinking, I really need to get a FI cut off switch.

So, I started thinking about where to mount it.

Side of the shifter?

Nahhh.

Side of column?

Maybe.

Somewhere on the dash?

Maybe? But where. Then it occured to me that I already got a damn switch in the perfect ergonomically located position when my hand is on the shifter in 3rd or 5th gear. Just stick out my thumb and it hits the cigarette lighter!

What if I was to disconnect the hot wire from the back and run the FICO wire in it's place. A cigarette lighter that is depressed in pretty damn close to being a short. It has to be to get 12 volts to make something hot enough to cause a fire in a few seconds. When I get home I will ohm it out. I suspect it will be less than 2 ohms which hopefully will be enough to pull the FI signal low.

And, this is the perfect stealth switch and also a handy theft deterent device.

Has anyone tried this yet?

One other thing. I will still have 12V as I have an aux. 12V outlet from the factory on the other side of the radio. So, I can still charge phones or use GPS.

And I've gone 49 years without smoking, so I think I'm safe there.

A button on the shifter or a whole shift knob with a button on it would work as well.. Alot of the dragrace guys will run one of these when they are spraying nitrous..

Yes, I could do that, but, then I have wires all over and if the button is on the knob, the chances of accidentally hitting it are too high.

It's too bad EOC isn't convenient with automatics.. I usually drive my S10 with my right hand resting on the column shifter.

I would apply Ohms Law to the question. Voltage drops across resistance. I take F. I. as fuel injection; is the signal voltage dependent or current dependent?

Software ate my edit:

I see you were going to do that when you got home. Never mind.

If that works it's a great stealth feature; anti-theft *and* hypermiling.

What I have read about FCO switches is that they just ground the signal. Being that it is electronic fuel injection, I assume it is all voltage with no current to speak of. There will be a high resistance dropping resistor which the voltage develops across. With no short to ground, the signalgoes from 0 to 12 v, but, as soon as you put a ground short it drops to 0vdc.

BTW, I measured it with my crappy meter and it measured virtually a dead short, so I think it will work.

Could someone tell me which wire I need to ground. It is a '97 3 liter V-6.

Here is my Stealth Kill Switch thread. Still working great after all these years.
http://ecomodder.com/forum/showthrea...tch-15943.html

Unfortunately, the injectors have 12v coming to them on red wires, and the wires going to the ECU are each different colors for each injector. The ECU grounds the circuit to fire the injector, so interrupting by grounding the signal will open the injector, not kill it. You need to interrupt the 12v coming in on the red wires. Go here and login with the username and password of tech/tech. Go to the bottom, "Auto Repair Reference Center Beta" and find vehicle and your wiring diagrams.

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