Where is the horn wire inside a 2003 Expo

[KSman]

I am getting ready to add an electronic air horn to my 2003 expedition, but cant seem to find the horn wire in the cab of the vehicle. Where can it be found?

 

[panda24619]

do what i did. get rid of the old horn and spice into its wires. idk about the 03s but it should be easy. just a ground and power. what horn are you looking at to do?

 

[corlon]

dark blue wire going up the column. depending the the type of test lght your using it will show 12 volts positive @ rest. when you depress the horn button the wire will go to ground.