Is your car horn not annoying enough? Try this on for size. Be warned, though, it doesn't work on all cars. In fact, it may only work on 1994 Acura Legends. But it could be worth a shot...
1. Locate your horn. This isn't the button you press to active the horn, its the horn itself. The best way to do this is with a friend. Have a friend honk your horn repeatedly, while you look for the source of the noise under the hood. The horn is usually shaped like a horn. This may seem obvious, but most people forget all common sense when they look under the hood. Once the horn is located, have your friend stop honking it.
2. Locate your car alarm. This also is usually under the hood. Like the horn, it helps if you set it off first. As the car owner, you probably know how to do that all too well. Again, once you find the alarm, make it stop that awful noise.
3. Turn off the car. Disconnect the battery. For anyone with an understanding of electricity, the reason behind this should be made clear shortly.
4. Cut the wires on the horn and car alarm. Then, with an all purpose wire, connect the wire that used to connect to the horn (got that?) to the car alarm wire. Reconnect the battery.
Presto! Now, when you press the horn button on your steering wheel, you're car alarm should turn on. Be careful, some car alarms sound like police sirens, and some police may not appreciate that.