Key less Entry

I Have a 2000 Quad Cab with key less entry. Is there any way to change the notification that the truck has been locked from horn to flashing lights? I currently have my key less set to sound the horn when I depress the lock button on the fob. I changed it, but the only option in the manual was to change it to no signal given. I would like to have the headlights/parking lights to flash instead of the horn sounding. I am willing to change wiring in the existing system if needed. Thanks in advance for any suggestions or ideas.

Call the dealership to see if there is more than that option. Call them and see what they say.