June 2009

The task of adjusting the points is a bit irksome, as it will annoy the neighbors! Basically, you turn the
adjustment nut while energizing the horn with a couple of wires until a good sound comes out of the horn.
After reinstalling the horns, all that was left was to install the horn button and horn ring. That job took a
little bit of patience in order to make the system work reliably, as described next.
To get the horn ring and button working right, I first had to adjust the longitudinal position of the steering
shaft relative to the steering column. This was because I had changed this positioning inadvertently as part
of the installation of a rack and pinion steering unit. This is not necessary on cars with stock steering.
Next came the task of trying to find the right replacement for the fiber washer that originally was fitted
under the little contact at the top of the steering shaft. As you can see in the schematic below of a generic
Cadillac steering wheel, the horn button (7.3785) is held away from the steering shaft by a conical spring
(7.3796) which rests at its small end against the nub of the contact (7.3820).
The contact has a flange and a shank (not seen in this parts diagram). I thought that the horns were
energized by the flange of the contact touching the top of the steering shaft. But that is not the usual
manner of blowing the horn. Instead, the flange is held slightly away from the top of the steering shaft by
the washer, even against the force of the horn button spring. When the horn ring is pushed, it causes the
contact to tilt slightly in the same direction as the horn ring. The lower tip of the contact apparently then
touches the inner wall of the steering shaft, completing the circuit. See my sketch (not to scale and a little
rough, but you will get the idea). The trick then is to come up with a decent replacement for the washer
that will be thick enough to keep the flange from contacting the top surface of the shaft and yet will allow
the horn to blow when the horn ring is tilted. Jay Friedman told me that some folks take a small rubber
band and wrap it around and around the shank to make a replacement. I tried that, with poor results. The
car had an O-ring on there as some previous owner's attempt at a repair, but it wasn't doing the job.
What I came up with is a bit of rubber grommet as shown in the drawing above. I cut the grommet with a
scissors to make a suitable collar to wrap around the upper part of the shank of the contact. To slip it over
the shank without removing the horn wire from the shaft, I simply sliced it lengthwise (split it) with the
scissors. Since it is captured in the bore, the split in the rubber is of no consequence. I found that a
grommet with a 3/16" ID worked well. Alternatively, a bit of rubber hose with a similar diameter would