In brief: The horn buttons on the steering wheel pick up ground through the metal of the steering column itself, then deliver this ground to the horn via a single contact that protrudes through the steering wheel frame and contacts a ring on the column.

I checked the horn bottons with an ohmmeter, and they are fine. The contact that protrudes through the steering wheel and contacts the ring on the column, I'm not so sure about. Can anyone confirm that the contact pressure for this pin from the steering wheel, is achieved simply by the springiness of that pin's wire, as it is held in the rubber retaining clip? I'm finding it hard to believe that this is what is relied upon to push that pin onto the ring on the column.

I took it all apart tonight, and verified that pin appears to be getting pushed up to its endstop through the hole in the steering wheel frame, but I did notice that the wear pattern on the ring on the column, appears to barely contact the very outside diameter of the ring. Once the steering wheel is mounted, I expected that this contact might be pushed off its endstop against the steering wheel frame, but it stays against its endstop, indicating it's barely (if at all) contacting the ring. The contact area of this pin is only a hollow circle, not a fuller flat contact area that I expected (not sure if this is normal or not).

I'm reading elsewhere that you can't buy individual parts for the steering wheel, so I may not be able to get a replacement contact pin.

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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto