My friend has an 03 F-150 with the 4.2 V-6 and auto. While I was driving it the other day, somehow I relized that if you hit the "On" and "Coast" buttons on the cruise control at the same time, it honks the horn. It only happens when the engine is on, and it only does it sometimes....... Just thought it was weird and wondered if it was maybe just some sort of short or if there was a reason for it. If anyone knows anything about it, let me know. Thanks.

 

I dont remember being able to do that on newer trucks but on older ones it worked most of the time. I'm not sure why it happens, never really thought about it.

 

If you were to remove the airbag/steering wheel(Caution-there is a special procedure for this) you will notice that there are more switches than you have wires. Supposedly the system works on different resistances - so you may have a loose connection, shorted/pinched wires.