Could BOTH my horns be bad?

As @67Dart273 says, be sure you are getting a good 12v, not just lighting the test light. And FWIW, i have fought a bad ground issue where the bolt threads in the rad support would sometimes be ground, and sometimes not. So I actually ran a separate ground wire from under the washer!

Keep at it as these other better experts are coaching. You WILL find it and fix it. OR, you'll just have to give the car to me and I'll be forced to change my handle to Demonx3!!