5 replies to this topic

[mini-mad-mark]

Hi all, helping someone with a Mk1 and I am struggling to understand how the horn works. (Never had a Mk1 personally)

 

Can anyone give me a short simple explanation please? I just want to understand when I put it together in case it doesn't work (or works not as expected...!) as I might not put it together correctly if I don't understand how its supposed to work.

 

 

 

The brown/black wire from the horn goes to the indicator stalk I can see and is currently connected , but what happens after that;  how does that form the earth path?

 

When you press the horn button I get that the little cap under the button touches the wire in the centre of the column and the metal part of the cap to make a circuit but how does that link to the indicator stalk?

 

I can also see that the horn push assembly has some kind of screw attachment but no idea what that does or how it makes the earth path

 hornpush.JPG   34.84K   6 downloads

 

 

I can also see that the short brown/black wire goes down and out of the column into a little bush and then touches the brass collar (slip ring commonly I believe) but where does it go from there?

 

Tried searching here and Youtube for a simple guide to no avail

 

Cheers in advance

 

[timmy850]

Ok so:
12v comes up with the indicator wiring
The sprung contact touches the slip ring on the column
The slip ring is connected to the wire coming up the centre of the column
The wire up through the column has a spring and touches the brass cup. The cup always touches the sprung wire, this is what returns it after pressing
The brass cup touches the black horn button (when you press the button) and this connects to the metal contact on the black horn button
This is connected to the screw underneath via the brass bent connection
The screw is earthed to the steering wheel
The steering wheel earths to the inner column which should complete the circuit via the steering rack

I have seen some people add an extra earth to the rack to ensure a good circuit.

Edited by timmy850, 21 July 2022 - 12:02 AM.

[Spider]

Ok so:
12v comes up with the indicator wiring
The sprung contact touches the slip ring on the column
The slip ring is connected to the wire coming up the centre of the column
The wire up through the column has a spring and touches the brass cup. The cup always touches the sprung wire, this is what returns it after pressing
The brass cup touches the black horn button (when you press the button) and this connects to the metal contact on the black horn button
This is connected to the screw underneath via the brass bent connection
The screw is earthed to the steering wheel
The steering wheel earths to the inner column which should complete the circuit via the steering rack

I have seen some people add an extra earth to the rack to ensure a good circuit.

 

That's just about it, but, if you don't mind my jumping in here, I think there's a bit more to it;-

 

Ok so:
12v comes up with the indicator wiring

 

Actually, I'm pretty sure it's,,,,,

12V from the fuse box on a Purple Wire to the Horn.
Leaves Horn on the other Terminal, as a Purple / Black wire.
This comes goes with the Indicator Wiring,,,,,

Then, as Timmy was saying;-

The sprung contact touches the slip ring on the column
The slip ring is connected to the wire coming up the centre of the column
The wire up through the column has a spring and touches the brass cup. The cup always touches the sprung wire, this is what returns it after pressing
The brass cup touches the black horn button (when you press the button) and this connects to the metal contact on the black horn button
This is connected to the screw underneath via the brass bent connection
The screw is earthed to the steering wheel
The steering wheel earths to the inner column which should complete the circuit via the steering rack

I have seen some people add an extra earth to the rack to ensure a good circuit.

Just jumping in here again,,,,,,

There's a contact from the outer Column Tube, via a copper or carbon block to a slip ring on the inner Column. The Purple / Black wire is connected to that copper or carbon block, this gives a 'rotary' connection from one to the other, but is a single connection only. If the Top (mechanical) Bush in the Column is worn, it can cause the Block and slip ring to loose contact and / or cause the coff coff 'spring' that gives some pressure to the block, to bend out of the way, so this is worth checking.

As Timmy mentioned, the other side of the Push Button is Earth via the Column and then the Rack after that, as the inner Column usually doesn't have any contact with Earth. Inside the Rack, the Earth path is in fact mostly through the Rack Ball Bearings, with a small bit going via the Pinion to the Inner Rack, to the Yoke. Because of this path, I would string recommend that a Relay be fitted, even with the stock Horn. I've found nearly always the top Bearing in racks from MKI's pitted from Electrical current.

[mini-mad-mark]

Right get it I think - cheers to both

 

Just to confirm it is brown/black wire by the way as an early mk1 

This:  Capture.JPG   7.57K   3 downloads

 

I just need to confirm something else now which I also found in another article about the flashing light in the end of the indicator stalk

 

I assume a good (electrical)  connection is required between the column tube and the indicator stalk to provide earth for the horn to work as detailed here (and the tell-tale light in the indicator stalk)?

 

On the car the column tube has been (well) powder coated so I guess some of that may need to be removed to provide a good electrical path? 

 

Cheers again

 

 

[timmy850]

You might need an earth from the indicator to the outer column for the indicator to work?

As mentioned above the horn earths via the inner column- and the inner and outer don't have any metal contact

[mini-mad-mark]

If I've understood correctly, the brown/black "earth" from the horn goes to the indicator stalk first, then through the outer column tube (hence why a good electrical connection is required there either by adding an earth cable as suggested or by removing some powder coat to ensure a good connection)

 

Then once it the earth is "in" the column outer tube it goes through the brass ring which is then connected to the wire in the centre shaft through the bush, and then goes to the horn push which connects to the inner shaft and via the rack to body earth

 

No wonder this was changed.....!