***Update I replaced the cutout switch right now and same issues****


I have a 2002 f350 I have had for a little over a year. When I bought it the cruise and horn didn't work and I didn't repair it thinking it was probably a simple issue.

Upon research I thought the clockspring to be the most likely culprit since both the horn and the cruise don't work. I was concerned over one issue though.

The horn DOES work but only when the ignition is turned off. I read another post where a technician told another person with the same issue that the horn has no ignition component, but his did the same thing.

His turned out to be a loose wire in the fuse box. Mine is not that.

I just replaced the clockspring and it is doing exactly the same thing. I tried to do a button test on the CC buttons however the cruise light never lights on the dash. Never and I pulled the cluster to swap bulbs and the light bulb was good.

My theory is the horn and Cruise are 2 independent issues parading as a common failure. I bought a new cutout switch tonight I will try but it looks like the previous owner already replaced it. Rather than using the harness to switch the connector they just went ahead and cut the factory harness and crimped a new head plug on it. I don't even know if they put the wires going into the correct place.

At this point I believe I would have to replace the entire harness to fix that lazy mistake.

Fuses are all good also.

Any ideas on what the issue could be?

 

For what it is worth I have read posts saying the horn relay is not serviceable on these trucks. You can hear the relay click when the ignition is off. When the ignition is on it doesn't click(the same issue others reported). Also, it has an aftermarket alarm and keyless entry that appears to have another two relays wired in.

I pulled the fuse box down but don't have any idea which wire coming out the back of the fuse box is to the horn.

 

This is just a complete guess but it sounds like a bad ground to the steering wheel controls, Key off there would likely be enough backwards draw through the other circuits to trigger the horn????

 

Maybe, I would have to go fishing for where that harness grounds out. The two connectors hook up under the dash and run out from there. The sheer number of wires added for the alarm has my headed hurting and of course I have no wiring diagram for the alarm so I have to try and figure that out too. I was really hoping it was something easy like a clockspring since the cruise was out too.

I would 100 million times rather change 2 clockspring than dive through tracing wires under the dash to try and figure out where the issue is.

 

Aftermarket alarm systems can cause some strange issues, is it possible to disconnect the alarms computer from the truck?... Basically unplug the alarm?