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Re: Horn connectivity

Just a thought, but could it be that the wire is too thin in the steering column and elsewhere.
Like me the thicker the better.
Voltage drop sounds like the problem ?

Location: The Centre of the Universe

Re: Horn connectivity

I had a similar problem on my 1929 fabric saloon. The horn button had been wired incorrectly on the live side of the horn using two wires. The button was trying to connect the two together.
The wiring diagram differ between versions. Some show it wired like that which really can't work, and some show the switch on the other side of the horn so live is fed to the horn which is earthed by the button, which is how it should be with one wire up the column.
Also the contacts inside the button were crude and I remade them. No problems since.

Re: Horn connectivity

Good afternoon all. Jim has made an important point that the horn is connected to a positive supply and dropped to earth via the horn push. I have seen conflicting circuit diagrams for this where the horn is earthed and receives a positive supply via the button.
I have been restoring Ruby horn/indicator units for some time but would like to source some thicker 4 core multi cables than those readily available and would advocated the fitting of a relay.
Regards
Stuart

Location: Staffordshire, the creative county.

Re: Horn connectivity

Stuart Joseph
Good afternoon all. Jim has made an important point that the horn is connected to a positive supply and dropped to earth via the horn push. I have seen conflicting circuit diagrams for this where the horn is earthed and receives a positive supply via the button.
I have been restoring Ruby horn/indicator units for some time but would like to source some thicker 4 core multi cables than those readily available and would advocated the fitting of a relay.
Regards
Stuart


Hi Stuart,
in theory you will always have a permanent feed from the NON earth side direct to the horn and the earth going to the horn push which completes the circuit when pressed.
So dependent on the year of the car, it's possible to have a circuit where the car is negative earth having a permanent positive feed to the horn itself and a negative feed via the horn push to a negative earthed car.

Equally, again dependent on the year the change was made in production, you can have a car whereby the opposite applies and have a car with a permanent negative feed to one side of the horn and a positive feed via the horn push to a positive earthed car.

I believe the main changeover from negative to positive earth with 'our' cars was circa 1936.

Regards Steve V.

Location: Polegate, East Sussex, United Kingdom

Re: Horn connectivity

Thanks everyone for your input. It does seem to be a voltage drop problem, because when I take the Rist off the car and put some jump leads to it, it blares like a good 'un. Fitted to the car it just won't go. I've decided that I will rewire the lot, with a relay to switch the main current. That should do the trick. The horn wire up the column is a pretty hefty one so that should be OK. Have tried a jump lead direct to battery earth terminal and the back of the horn quadrant and it makes no difference so I guess the column is properly earthed.

Just need to sort myself a relay and some decent wire.

Happy days! I'd be dead bored if I didn't have something to mess about with.