Corvette Security Additions

Well, as far as being able to honk the horn normally while driving, you could do it this way. Attach the siren's positive wire to the horn's positive wire. Attach the siren's ground wire not to a ground...but to the car's main ignition wire. When the car is on, the siren will not work. When the car is off, the ignition wire will give the siren a ground, allowing it to work. Even though we don't typically fuse a ground wire, you should in your case. Attach an inline fuse close to where you pick up ignition power; this way, if your wiring shorts out to ground, the fuse will just blow---your car will still be driveable until you can fix the trouble. Also, you don't necessarily have to go to the steering column for the ignition wire---you might find a wire underhood that will test the same way. If there's an underhood fuse box, I'd start there. I still haven't thought of a way to keep the siren on steady while the horn is honking on and off, but at least you have a solution to the siren-while-driving issue.