VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt horn button

can anyone tell me how the horn button is supposed to work in our '40 kc 1/2 ton?..

currently, it is without a horn button assembly...all we have is the steering wheel, held on to the (worn splines, thank goodness for the woodruff key) column with a nut and thick flat washer...

when we remove the nut & washer, we see two holes that look like they are for the horn wiring, but if so the wire would be crushed by the flat washer...

we assume there are no commutators for this vintage?..

we've seen the replacement horn buttons in catalogs with what looks like two wires dropping out of the bottom, but think that we're also missing something else...

epi

I believe your application uses a bushing in the steering shaft tube with a brass ring on the top with a hole on each side for the guide/ground wires on the back of the horn button to pass through. The guide "wires" are also part of the contactor mechanism that creates an electric circuit path from the shaft outer tube and the brass ring on the top of the bushing (which has a wire that runs out the back of the bushing inside the tube to the horn relay).A picture is really worth a thousand words with this situation! The bushing can be removed by removing the steering tube and pushing the bushing out the top of the tube with a suitable piece of pipe. Chevys of the 40's carries the bushing that should fit your application. The washer used under the steering wheel nut must not be too big for the horn button contactor wires to pass freely through the guide holes in the bushing. Hopes this is accurate and helpful.

videoranger,

you're right about a picture, but thanks for your description...

ok, right off the bat, we would say that the steering wheel-to-column washer is too large, as it completely covers the two horn wire holes...in fact, the wire holes in the steering wheel are so close to the shaft that the nut itself would have to be tightened in a fashion that the flats, rather than the points, would be adjacent to the holes so as to not interfere...

is the correct washer this small in diameter, or does it have two "notches" to accomodate the horn button wires?..

also, I scooped out the hardened, 60-year-old grease inside the column housing and can see a "shoulder" around the shaft about an inch down...is this the bushing you referred to, or in other words, when installed, do the horn button wires protrude about an inch past the rear of the steering hub?..

additionally, there are no visible wires exiting the steering column...this truck's been rewired at least once before our ownership...where would the original horn wires exit the housing...I'm guessing around the back of the clamp at the dashboard?..

finally, I couldn't find the bushing, but cot40's also lists a "horn button cup"...I'm assuming that I'm also missing this part...

epi

actually I'm going by the set up on my '38 passenger which I believe is simular to your application (someone please join in if I'm incorrect)The S wire as pictured on cot40's site would rub on the inner surface of shaft tube through slots on the outside diameter of the bushing, not next to the shaft. The S wire protrudes downward about 2.5" on each side and the rubber under the horn button acts as the spring. When depressed the S part of the wire under the horn button contacts the brass ring on the top of the bushing to complete the horn relay ground circuit. On my '38 the horn wire from the bushing contact ring extends down the tube and out the lower part of the tube through a grommet. You should probably give the cot40's folks a call on this one as they are more than likely familiar with your application and the need replacement parts. I noticed they listed the horn button assembly but not the bushing on the web(the catalog shows the bushing)

Excuse my confusion, the ends of the S wire do not pass through the bushing but do extend past the steering wheel hub. when the horn button is depressed the ends of the S wire contact the brass face of the steering shaft bushing.

videoranger,

thanks for the helpful descriptions...at least now, we're beginning to get a sense of how it's supposed to work...

epi