I bought my 02 F150 SuperCrew 4x4 (5.4) in October 2013 and neither the cruise nor the horn worked. My truck's symptoms were not the same as many other posts I have seen on here, so I figured I would share.

Symptoms:
1) cruise never worked (obviously)
2) the horn only worked with the ignition off. If the ignition was off, you could press the steering wheel and it would honk, also the door lock on the key fob would make it honk if the key was out; but as soon as the key was turned - no horn
3) the cruise diagnostic self check would give flashes after I pressed the off and on buttons on the steering wheel, but nothing happened when I pressed any of the buttons on the right side of the steering wheel.

The lights on the steering wheel buttons also always worked.

The cruise recall work had already been done.

The solution: it was the speed control (cruise) servo. I bought a used one for $50 off of eBay (a new one would have been around $500) and now both the horn and the cruise control work. The only problem I encountered was the top bolt on the servo bracket sheared off with very little force when I tried to unbolt it. It took me about an hour to get the other half out of the hole with a pair of vise grips and pliers. The bolts looked like they were made out of aluminum. I replaced them with steel ones. For anyone replacing a servo, unbolt the bottom bolt first. I don't think the top one would have sheared if I had done the bottom one first.

This is my first post on here, but I'm not new to forums at all. I wanted to share because I know how frustrating it can be when you see someone that has the same problem as you, but they never post a solution. It was a collection of things I saw on here that led me to believe the servo was the culprit, so thanks to all of you who post on here! It really does help. I'll try to stick around and offer help when I can.