Series 2a Horn

[JDNSW]

After getting back from Queensland I found that the horn on the 2a did not work. Since the problem is common with negative earth 2as, I will go into a bit of detail.
The steering wheel centre horn push on this model contacts the live wire from the horn itself via a copper collar on the top of (and insulated from) the outer steering column. The push button earths the circuit via the inner steering column, relying on contact through the bearings for the earth return. The moving contact and the copper collar are protected by a sleeve attached to the steering wheel, which also doubles as the contact for the rubber tyred wheel that operates the self cancelling on the turn indicator switch.

To get at it pry off the cap on the steering wheel centre and disconnect the wires. Loosen the nut on the inner column a few turns and wiggle the wheel until it is loose, then remove the nut, locking washer and the steering wheel.

The sleeve mentioned above can now be removed by undoing two screws from inside the wheel.
The problem was that the wiper contact, a springy piece of copper, was not making contact with the collar. There were two reasons for this - the rivets holding the fibre mounts for the wiper contact were slightly loose (probably due to the drought shrinking the fibre insulation), and the rivetted on threaded bits on the sleeve were loose, allowing the sleeve to tilt slightly under the pressure of the turn indicator switch.
Both were tightened by gently compressing the rivetted bits using a pair of flat ended punches, one held point up in a vice. Particular care is needed with the threaded bits, as they are made of aluminium, and if you are not careful you will need to rethread them (I think they are 6BA).
Assembly is the reverse of the removal procedure, although I rubbed the collar with powdered graphite in the hopes of minimising wear on the wiper contact.

John

[Dinty]

G'day All, John, been there, done that many times, buggers of things they are Cheers Dennis

[JDNSW]

G'day All, John, been there, done that many times, buggers of things they are Cheers Dennis

Only my second time, but I thought it needed spelling out for those who may have recently got one! I was very tempted to put a spring behind the moving contact, but it looked like too much work!

John