Hi J,
there are three phillps head screws - these pass through insulators.
The aluminium contact gets deflected over the brown bakelite insulator.
Contact is made from the brush of the horn lead to the brass plate of the steering wheel hub.
Whilst on the topic of horns, can anybody recommend a way of 'beefing' up the sound without too much trouble or alteration? I find that some people either do not see me (how can you miss a pink FB) or are just driving around with their head up their.......which may be a growing trend with Sydney drivers. So any suggestions? (Pretty much nothing has been altered on my car except the brake fluid resevoirs.)
Theres an adjusting screw on the back of the horn that can change the tone a bit. Another option is to mount a new horn (from Repco/Supercheap) using the original bolt holes and piggy-back the wiring off the old horn so both work at once (doesn't look too stock, but a lick of flat black paint and some black wiring makes them almost dissapear... probably better than getting run into !).
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.