Most of the time when the drivers side air bag goes off ,, it will damage the clock spring in the steering column ,, so the horn will be inop and the cruse control will be inop and after you replace the drivers side air bag , it will still have a code in the air bag mod for the drivers air bag has a open all due to the clock spring is bad and has a open .
the clock spring is a spool of wire between the steering wheel and the steering column that allows the steering wheel to turn and still maintain wire conections to the air bag, cruse switches and horn ,
if the truck has a Ford remote ,, push the lock button twice ,, and see if the horn blows ,, if it does then it will tell you that the horns are working and you may have a bad clock spring
if the horns work with the remote ,, then you can find the YELLOW / LIGHT GREEN wire on the mid section of the steering column at the clock spring conector and ground this wire ,, this should make the horn blow
any more info , just ask , we can go back and forth on this page ..