So I'm having trouble getting my horn to work and I think a picture will really be the only answer.
Currently, with my steering wheel installed (but the plastic horn button cover off), there is about a 1/4 inch gap between the plastic wheel hub and the plastic hub of the steering wheel column. I can see in this gap a small brass contact (little cylinder about 1/8 inch across, like a pencil eraser) sticking up, but not reaching the underside of the steering wheel (where there are metal rings). If I stick something metal into this gap and jump the metal rings to the brass button, the horn sounds. This surprises me as I assumed the circuit would not be completed until the horn buttons on the wheel are installed and depressed. Thus I assume this is the horn contact, and the plastic horn button cover when installed connects these and breaks the circuit until the buttons are depressed?

So my question is: does it sound like a wiring problem or is it just that the wheel is not seated fully? I think a side view picture (and an open one of the turn single switch and horn contact) would best help. Also, if the wheel is not seated fully, how do I push it down further? The bolt is very very tightly on right now, and I don't think I have 1/4 inch of travel left by tightening it. Is there a trick during install to push the wheel on down further before securing with the bolt?

 

The piece that looks like a pencil eraser is called a brush and is part of the turn signal switch. It's spring-loaded, and normally pushes against the contact ring on the bottom of the steering wheel. Assuming this truck is the '73 in your profile, then your truck has a horn relay, and this brush is the ground-side of the horn relay coil. When you press the horn pad, you ground the ring on the underside of the steering wheel, which is in contact with the brush for all positions of the steering wheel as it rotates. You're probably shorting the brush to a nearby ground when you stick something metal under there, which closes the horn relay and makes the horn sound.

If you can see that the brush is not in contact with the underside of the steering wheel, then either the brush is worn out, or the steering wheel can't seat because it's the wrong steering wheel. Since you can't tighten the wheel down any further and there's still enough gap between the wheel and the column that you can see the brush, I'd guess it's the latter (wrong year steering wheel).

 

Wrong year steering wheel is a definite possibility...suggestions on how I would identify if that is so?

Also for a fix- how about adding a short spring on top of the brush to extend it to the steering wheel contacts?

 

Can you post a picture of the steering wheel in question?

I don't recommend trying to extend the brush; a spring would be hard to secure, and if it somehow detached, you'd risk having the horn stuck on if it shorted in the right place. Or it would short something in the turn signal switch. A spring also wouldn't be able to stand up straight as the wheel turned, and could get caught. Best bet is to fix the problem with the correct parts.

 

here are three photos of the steering wheel: one is head on, the others show the side gap and the horn brush not making contact:
Ford Truck Enthusiasts Forums - PRUSue's Album: Fixing the truck - Picture

Ford Truck Enthusiasts Forums - PRUSue's Album: Fixing the truck - Picture

Ford Truck Enthusiasts Forums - PRUSue's Album: Fixing the truck - Picture

 

Can you press down on the wheel and have it come in contact with the brush? If so have a buddy hod it and there should be a clamp like thing in the engine compartment on the steering shaft. Loosen it and slide it up towards the wheel and tighten it back down.

 

Yep, that's the wrong steering wheel. That looks like a later-model (77/78?-79 style) steering wheel which I don't believe matches to the earlier column. Someone correct me if I'm wrong.

 

1971/77 steering wheels (except '75/77's with Speed Control) are essentially the same. Also used on 1974/77 Bronco's and 1975/77 Econolines (w/o Speed Control).

1978/79 is different and there are two different diameters (15 1/2" w/P/S vs 16" w/M/S). Also used on 1978/79 Bronco's and Econolines.

The horn pads are specific to 1971/77 / 1978/79 / Speed Control horn pads are different.

1973/77: There are 3 different T/S switches: M/T / A/T / 1975/77's with Speed Control.

1978/79: There are 3 different T/S switches: Tilt Wheel only / M/T w/o Tilt / A/T w/o Tilt.

 

Thanks for the follow-up; I knew the break-away was somewhere in there.