Why is this earth on the hornpush?

[DEEMAN]

There is an earth on the hornpush I have. It is on the ramp(!!!) and I cannot believe it is original - doesn't even look like it.



I see other, more original, hornpushes, and they also have an earth but more sensibly placed.



But my question remains. Why should there be an earth there at all? Testing purposes? Surely not needed.

Or am I being dim

Ian

[914 KEV]

There is an earth on the hornpush I have. It is on the ramp(!!!) and I cannot believe it is original - doesn't even look like it.
But my question remains. Why should there be an earth there at all? Testing purposes? Surely not needed.

Or am I being dim

Ian

Yes it should be there. It is a switchable earth.
This plate is insulated from the rest of the horn push and when pushed will make contact with the steering wheel to make a circuit.

The connection on the plate can easily break off if not careful when connecting the wire and removing it again when the horn push is removed from the steering wheel..

[Lightweight_911]

I think there may be a difference between the set-up on a 911 vs a 914 ...

Certainly on the LWB early 911's (& 912) I've owned these are the connections:


Brown & white wire (from the relay) connects to the horn contact 'slip ring'

Brown (earth) wire connects via a ring terminal to one of the steering column housing screws - see item circled in red :



Once everything is assembled, when you press the horn it completes the earth connection (via the spring-loaded horn contact) to the slip ring & hence triggering the horn relay.

There is no additional earth wire connected to the horn pad.


.

[DEEMAN]

Thank you both. So the 'spare' connection is not used in my car.
Everything is wired as per your description and excellent picture Andy.

Onwards with the project - but it is a bit too cold in the garage as yet even though the sun is shining.