I have a 2003 Chevy Silverado HDLT Crew cab..the horn quit working. If it's a fuse, where do I find it????

Yes, it is the fuse. it's a 15 amp fuse located in the under hood fuse box.

But the reason the fuse blew, is water intrusion to the right side horn. water accumulates in the horn and when you press the horn pad you create a short, and poof the fuse pops.

You can replace the fuse only, but that's a temporary fix.

You need to replace the fuse & the right side horn.

If it is the fuse, the fuse box is underneath the dash on the left side above the kick panel. If not, there is another fuse box under the hood. If not the fuse, it could be a dirty switch contact or an unplugged wire to the horn.

There should be a diagram on your fuse box cover, just look for it there. There shoud also be a diagram or list in your owners manual of the fuses.