Hi XXXXX. Thank you for asking your question on Just Answer.
If the horn beeps when the security is set, then the horn relay and the horns themselves are most likely OK. You could verify that by pressing the "panic" button on the remote and see if the horns still work with that.
About all you have left is the horn switch itself, inside the steering wheel, as shown in the schematic below, at the lower left.
Please let me know if you need more information.
Take Care, Greg A.
Master Troubleshooter
Working with Electronics & Cars for 25+ Years