Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hello I will help you with your question,
Is the airbag warning light on?
Do you have a voltmeter?
Does it have a horn chirp when the alarm is set?
Sounds more like the horn itself is the problem. Can you remove the second relay from the bottom in the box next to the battery and find the #30 and #87 pin socket? It should be marked on the relay. If it is not let me know and I will find the pin numbers for you. It looks like you want the #2 and #3 sockets.
Short those together and let me know if you can make the horn sound that way.