horn

ihave 99 silverado and when i go to honk the horn sometimes it will sound and sometimes it wont ,had this same question while back ,did the things the guys told me to do ,thats the problem it only sounds sometimes thought i had it fixed,when i got my inspection done the guy past it but said something with the alarm system was making this happen,,,do you guys have any other ideas, :confused:

Is the Ground on the horn good?

Is the Air/Bag/Center of wheel making good contact?
Sometimes the ring inside the steering wheel get's corroded and doesn't make contact. Try holding the horn button down and spinning your steering wheel; You may find a few dead spots...
I had that problem on my 90 Blazer had to clean the ring every few years....