It works for either,but if anything I'd want to interrupt fuel. It start runs dies 10 feet away and now it attracts attention. Yes it is possible with a mechanical pump we've discussed all of this. Best bet imho is an instant on alarm,leave the door unlocked,no lights no stickers,no warning. Ah! a sucker, but as soon as the door opens whoop,whoop,whoop. No broke window,no shattered column,because that's what's going to happen first,before they figure out the truck won't start.
^What he said!
Haven’t done the alarm but totally subscribe to the plan of starts, runs, dies. Crank til the battery is dead and then leave it because it’s attracting attention hopefully in the middle of the road.
Easy with our ‘86 with electric fuel pump (aftermarket system).
Little more of a challenge with a mechanical pump engine. Maybe consider an economical electric fuel shutoff solenoid hid underneath behind the tank switchover valve cover. If it’s dual tank.
My hidden switch is different. Considered the cig lighter trick but it gets used for charging phones.
I tested the no fuel theory. The Edelbrock on the truck will start and run long enough to idle it for a bit and drive a couple hundred yards. Sitting idling it will run for almost a minute.
My goal is if it gets boosted somewhere in public (in town here, from typical places like a parking lot), it’ll run long enough to get out into a main road or at least down the street. And then it’ll just crank with no fuel supply from either tank.
If you were going for the most simple, I’d intercept the neutral safety switch wire. That’s the least hackery of wiring. Except that’s a no crank so immediate knowledge by a thief that it has a kill switch.
IMO it’s as much about confusing the theif for a bit as it is scaring them off (alarm).