How do I disable my horn

Check your fuses. It varies from car to car but you may have a fuse dedicated only to the horn unit. In that case you can just pull the fuse without affecting anything else..

Other than that you will need to pull the wiring connectors off the horn unit and tape them up to keep any moisture and dirt out. Hopefully that will not trigger any issue with the security system.

In order to disable a car alarm, an individual will have to locate the horn that was put in and disconnect it, or they will have to fix the problem with the alarm. You can disconnect a car's battery to disable a factory car alarm with help from an ASE-certified mechanic.---------------------------------------------------------------------------------
fgtech galletto 2-master

I can tell you where the problem is, and what it is, but I can't tell you exactly how to fix it, not being there to see it.
It is behind your horn pad on the steering wheel, that's where. What happened is the horn wire there is being grounded unintentionally.
Normally, when you press the pad to sound the horn, you are grounding the wire from the horn there. A metal clip makes contact with the horn wire, grounding it so the horn will work. Something on yours has come out of place, maybe a metal button or spring or clip is extending too far and touching the horn wire when youj turn the wheel.
If you can get behind the horn pad or button, you might spot the problem. But that is where it is. Good luck.

Usually a problem in the steering column, have the steering wheel checked

disconnect battery then call dealer

Your ground for your horn button in the steering wheel is stuck in the on position and will require dissassembly.

mine is doing the same thing! happened this morning at 3 AM and had to unhook battery to make it stop...it only happens when it is very cold outside! someone please advise on a remedy!

Is the alarm causing the horn to honk? If so, you need to figure out what is causing the alarm to trigger, which could be any number of things.
Or, the panic module could be failing.
It is least likely to be the horn ring unless the only way you can get the horn to stop is by "beating the horn button on the steering wheel".

If it is, then you can replace the parts for the horn button, but you will need to get an assembly manual for the vehicle. Be sure to disconnect the battery before attempting to remove the airbag module. If it goes off, then you risk injury, and, they are not cheap to replace.

Hello.
Changing out the old battery, you may somehow shorted something out in the car. You can check this by seeing if you have any power going to the lights on the car and what ever else that uses the power when you turn on the key. Newer cars like yours usually cant short out, but if the lights and other stuff dont work when your check them, disconnect the battery and look for the fuse panel. Check ALL your fuses and make sure none of them have been blown. You can check that by seeing if the filament in them looks to be burnt or broken as if it popped.
You can also check and make sure that the negative battery terminal is on tight enough. Sometimes a bad ground can mess everything up. As your doing this, before your reconnect your battery, go under the hood of your car and disconnect the horn. This will allow you to work without the horn blaring. To disconnect the horn, its just a wire with an end that simply slides over a metal tab, just give it a pull and it should come right off. You may have two horns so check both sides of the radiator. Hope this helps!
-Steve

I have seen this happen in damp areas and very cold areas where condensation sets in and shorts out the circuit, thus soundig the horn. Good luck and remember to rate all the solutions you get, thanx.