1972 Twin Cam
I've fixed the problem but it's not straightforward.
As the car was bought as a half done project it's not clear what parts came off of the original and what have been sourced along the way. I have found plenty of
parts that are not correct for a TC (or even a Europa)
The steering wheel boss was shorting against he slip ring (photo 1) as soon as it was placed on the column. I made some adjustments to the centre column to create a gap
and added insulation tape in a few places.
Pic 2 is the back of the boss, the spring contact rubs against the slip ring on the column cowl to pass the 12v supply, the cable goes through the wheel into the horn push.
Pic 3 is the back of the horn push showing the 12v supply cable.
Pic 4 is the front of the horn push showing the metal contact rings that make the circuit when you push the horn. It's a sprung loaded mechanism that is insulated from the rest of the
wheel & boss. The green side is the earth route, the red circle shows the gap and the 12v supply is connected to the top ring.
Pic 5 is the horn push on the wheel, the washer and nut hold it all in place and the centre cap clips in place on top.
With this type of horn there is no contact 'pencil' or cage fitting used. I'm not certain the column and steering wheel are actually a correct match but I have made it
work nicely. The wheel sits perfectly within the steering column.
Hope this is useful if you get similar problems.
