sijwhite said:

Switch -> fuse -> relay -> horn is how I'd do it.

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dave66 said:

I bought a TD4 at the end of January, shortly after taking delivery I found neither of the horn switches/buttons on steering wheel work. The horn itself seems fine, I left door open and used key fob to try lock car, the horn sounded. I'm guessing it's a problem with the rotary coupler and waiting for the dealer to get one to fix issue.

In the meantime it means I'm driving a car that is technically illegal as it doesn't have a working horn.

So I'm thinking of wiring up a simple push to make switch to the horn, just wondering if anyone has done this and if so did they wire directly from battery to switch to horn or did they splice into another cable somewhere, any guidance would be appreciated.

Thanks

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cremator said:

as it had a replcement radio fitted to it

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PaulMc said:

The horn buttons on the steering wheel, switch the Purple/Yellow (PY) wire (from the horn relay) to earth.

The alarm ECU does the same to activate the horn.

To put another switch into the horn circuit, you need to connect into the PY wire and use your new switch to switch it to earth.

The easiest place to access the PY wire, is in C0082 at the rotary coupler -

You could release the terminal from C0082 and insert it into a new connector with a wire running off to your new switch.

That way you can put the PY wire back into C0082, when your rotary coupler or horn buttons are sorted.

I can supply compatible connectors and terminals, or a 'plug-in' adaptor to go between C0082 and the rotary coupler.

This would have all the circuits, plus a wire of whatever length you required spliced off of the PY wire, to go to your new switch.

PM me if you're interested.

.

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PaulMc said:

The horn buttons on the steering wheel, switch the Purple/Yellow (PY) wire (from the horn relay) to earth.

The alarm ECU does the same to activate the horn.

To put another switch into the horn circuit, you need to connect into the PY wire and use your new switch to switch it to earth.

The easiest place to access the PY wire, is in C0082 at the rotary coupler

You could release the terminal from C0082 and insert it into a new connector with a wire running off to your new switch.

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dave66 said:

Paul,

Could you confirm that I'm reading things right from diagrams, my reading is that I essentially need to connect PY Pin 3 on C0082 through a switch to B Pin 4 on C0082? Or is there an easier location to connect to a good earth?

Thanks

Dave

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dave66 said:

Yep, the radio was replaced before I got the car. Now has a a Sony CD Player. I've had a look behind the radio and there appears to be 3 wires in the original loom that are no longer connected to anything.

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