Is it an erratic alarm sound or is it consistent? If its erratic, I would check the wiring. If its steady, I suspect the horn relay is at fault. The relay opens and closes the power circuit to the horn. So in a nutshell, it sounds like the relay is opening and closing the power circuit slower than it should be.
The relay for your car isn't expensive. At autozone, you can find one for 12.99 (part number: 19264)
Wednesday, May 19th, 2010 AT 10:27 PM