How to disconnect horn on toyota corolla - Corolla Toyota Cars & Trucks

SOURCE: Horn not working

check fuse then check relay or just check for power on the horn it self

SOURCE: Horn doesn't work (worked intermittently for a while)

Dear Mr. bclester, you have not indicated whether you have checked your fuses. First check them and then if they are ok, check the horns themselves. Remove them individually and test them on your battery. Are they fine? Let me know so that I can advise you on what to do next.
arturocruz

SOURCE: Horn location for 2005 Toyota Corolla?

It should be under your hood somewhere near the front grill

SOURCE: 2005 toyota corolla horn doesn't work

You can replace the horn. Check to see if the wires connected to the horn have power. Check with a test light. If power is present then the horns are bad.