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Hi, I believe I can help. Is it the actual car horn or does it sound like an alarm? Typically this model has problems with the alarm horn and not the actual car horn.
The problem with the alarm horn is it has no fuse. It actually has a separate battery built into it so a thief can not disable it easily
The extra battery is built into the alarm horn assembly so disconnecting it won't do any good. The only way to shut the horn off is to get it replaced. The problem is the faulty circuitry of the alarm horn which causes it to go off randomly.
To remove the alarm horn is not easy, its located in the front wheel fender well area and the wheel and fender liner will have to be removed to access it. Unfortunately the best solution would be to drive it to a repair shop or have it towed immediately to have it replaced since eventually the horn will drain your battery and the engine will not start.
Yes, unfortunately it is very annoying. The only way to shut it off is to remove it since it has its own power supply
I can walk you through it if you have the tools or equipment. If not I suggest you drive it to a shop before the battery dies. If you don't want to drive it with the embarrassing noise, I suggest you get it towed soon since eventually this will drain the battery.