I have everything working on my 77 Ford Explorer accept the horn. I read about a ground wire around the rag joint on the steering coloum which I have yet to check. I took apart a 75 truck and found a heavy spring between the coloum and the steering wheel. Would this be needed to complete the horn circuit? Makes sense, but my truck was missing the spring. I will install it tonight and see what it does. Just wondering what you folks thought.

 

Don't know about the spring - I initially mis-read your post and thought you meant a horn button spring...

Most likely, it's the wire bridging the 2 halves of the rag joint - the disk in the rag joint acts as an insulator so the wire was used to bridge over the disk and provide a current path through the 2 sections of the steering shaft...

 

C3DZ3520A .. Coil Spring...Steering Column Upper Bearing.

Fits all 1963/79 F100/350's.

The upper flange has the bearing and its retainer pressed on. This spring sits on top of the bearing on one end, to the wheel on the other end.

What this spring has to do with how the horn operates, I dunno.

It could be the horn switch, it's part of the vinyl horn pad and is the same 1971/77 except 1975/77's w/Cruise Control.

And...if you do have Cruise, you also have a horn relay (1976/79).

 

Some horn switches use a spring to keep the horn button from making connection until the horn is depressed. When depressed, the horn button completes the circuit and sounds the horn. The spring release the connection when the horn is released.

 

when you have the steering wheel off check the spring contact for the horn. it rides the collar on the back of the steering wheel hub. its also part of the turn signal switch.

anyway check for continuity on that spring contact and the small (blue/red??) wire on your horn relay. that will tell you if the wires are good to your relay

then check for power at your relay wire-yellow

check the other yellow wire that goes to the horn

if that all checks out good its a switch or a horn itself

 

Very good. I will check those things tonight. I grounded the steering coloum over the rag joint and added the heavy spring under the steering wheel, but horn still didn't work. The horn blows when wired to battery and the pad makes a circuit when pressed. The wire harness appeared unmolested when I installed it from a 75 truck. Got to me something simple as everything else works on the truck.
Thanks for the help,
Shane

 

Use a multimeter where your horn relay is. You should have a black (dark) wire there, it will be grounded when the horn button is pressed. If this never goes to ground then you have a problem with the ground in your steering column. If it does go to ground then check your relay.

 

Horn relay 1973/77 / 1978/79 with Cruise Control.