Horn

I noticed about a month or so ago when I would hit my horn, and hold it down for a moment it sounded like one of my horns was fading in and out. I took my car into the Ford body shop to get the bumper repainted and got it back, and now when I hit my horn it sounds really weak. Like only one horn is working. So I took the car back to the body shop thinking maybe when they took the bumper off they hit something loose. Well the tech told me he tested it and they are both working.. they both vibrated.. ?? vibrated.. anyway.. I don't believe him. I think he was telling me a bunch of crap b/c I'm a chic.. Point is my horn doesnt sound like it use to..I am very aware that both horns are under the same splash gaurd.. the tech tried that line on me 2. I went to check my fuses, but the guide in my owners manual doesnt match up.. go figure.. any suggestions??