Horn question!

Pictures??? The jumper wire hold it manually to were it's supposed to go and try your horns. Check the fuses too. The jumper might have shorted stuff out

 

Don't connect the little jumper wire, you'll blow your steering wheel off . JK

 

You could have went with it. Lol


Actually, is there an air bag?

 

And what a nice cabover that is in your avatar pix.
Are you driving that currently?
I always admired them in an odd non-aerodynamic design kind of way.
Had a chance to buy an International and 38 ft. alum dump w/wet line for 3 grand.
Run/drive and on the road, Needed resto inside cab, but would do that anyway.
Was always sorry I passed that up for the first of a series of 7 rollbacks.
I could have done some real industrial strength damage with that rig.

Check your fuses.
Take a cheapo power probe or meter and find the hot wires; there should be 2,
if you have 4 wires. I would have guessed 3 wires and only one hot.
Which begs the question, Where are the airbag wires?

So thinking 3 wires for the horns, (one hot, and two for each horn,) and one hot for the airbag.
Is it correct your custom wheel has no airbag? That needs to be covered in shrink tubing.
Or remove that fuse, also.

Really should be able to just touch them together and figure it out.
One connection should blow city horn.
Mark it.
Then find combination that blows air horn.

The one wire used on both combinations is the hot lead.

 

Not my Cabover. But I have admired the old Bullnose Kenworth. I still have a '93 International standup sleeper Cabover. Had 3 of them at one time. Wouldn't mind having a K100E. Almost had a really nice one a couple years ago, .But someone else bought it before I could

 

There's a guy near Wind Gap, Pa that has several; 4 I think, and runs them daily, also does shows.
I always give him the air horn salute in passing.

 

I seen a K100E for sale in Tn a couple mobtgs ago for around $15k, had new paint, solid white,

 

Coffee down the steering wheel plays havoc on that horn sensor,,gimmee the old days, PULL THE BLOODY CHAIN, MAN!!