I have a 1988 ford f 250 that the horn and the curise control stopped working the fuse is fine if there is a relay for this where would it be and if not how can i fix this

Fuse/Relay Location: 24
Fuse Amp Rating: 20A
Passenger Compartment Fuse Panel Description: Horn Relay Feed

http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/08f23og1e.pdf

I would suspect an underhood fuse, the steering wheel clock spring, or a wiring problem. It's cheap to triple check all the fuses. The other two will require some troubleshooting to figure out. Since the horn works with the keyless entry, the relay, the horn, and its control wiring seem to be ok.

could the ingress of water have got inside the control box?? or the wiring connections causing them to corrode ?' other than that i have no idea as i havent work on many of this vehicle here in spain.sorry for no instant fixya type answer

Horns die like crazy on these. put power to the horn and make sure it works. The horn button is possible too the clockspring connection at the steering wheel. Find the wire in the harness under the colum that works the horn its black and it's on one end of the connector. with a test light hooked to ground, touch the wire and it should light dimly and the horn relay shough click. if it does the horn is likly or the fuse is blown two wires at the horn one shold be hot all the time and the other becomes grond pushing the horn button if thats good the horn is bad

have your mechanic check you STEERING WHEEL control module its the unit the control the function on the steering that communicate with veh ecm

check fuse and also check the wire going to the horn and check the inside of the horn too and check the ground

I’m happy to assist further over the phone at https://www.6ya.com/expert/john_2c7bb9c157d0baa8

You might want to check to see if it was disabled by Ford first. Ford had a major recall on Curise controls in these vehicles and many were disabled while parts were being ordered. You should be able to stop by a Ford dealer and let them check by Vin to see if yours has had the recall done. If not it may save you some money and get it back working and working safely when they do the recall work on it. Ford did the recall due to the curise controls activating by them selves if I understood the dealer correctly when he did my mothers vehicle. Did not cost anything for the recall work and this includes even if you were not the original owner and purchased it used.

Remove the horn relay.

To find the horn relay:
"look under the hood on the left, front side of the car there's a somewhat triangle shaped box with fuses in it. It has 1 latch @ the top(left side of the box) & 2 latches @ the bottom(right side of the box). Open & pull off top. Under top will be names of the fuses & relays you will need to take it out and take it with you to the parts store so they can match it up with one they have they may have to order it call first. "

from: WikiAnswers

CHECK HORN RELAY .. most of the time its not the horn switch its the relay that's stuck in the in position.

The horn(s) burn out very easily, also there is a relay, press the horn button repeatedly and listen for a click noise (it may be under hood), if you don't hear it the relay may be at fault, if you do the horn is burned out, not uncommon.