How do you change the fuse for the horn in a 2003 Chevy suburban?

The horn fuse is located in the fuse box under the hood on the drivers side of the truck. Lift off the cover of the fuse box and the underside of the cover has a labeled diagrahm. Find the 15 amp fuse. Remove and replace. However, I also have a 2003 suburban and found that the problem originates with a short in the horn assembly in the steerng wheel. The horn will keep working as a lock/unlock indicator, but will only work one time if the horn is activated on the steering wheel. It will keep blowing fuses.