the easiest thing to do if you can't find tha appropriate wiring diagrams would be to open up your steering column and trace the wire. it's the ones connected to your stock horn buttons. they are a simple ground paddle type switch. get a decent length of wire and ground one end to the chasis of the car. take the other end and when you connect it to the appropriate wire the horn should go off. this is exactly what your alarm will be doing - providing a ground to that wire. idk if there was a problem with the wiring in my wheel (my buttons suck major ass) but the alarm shop chose to tap the horn relay in the bay instead at the fuse box. this is another possible solution but requires excessive wiring.

-marc