C5 X7 horn wiring diagram

[aerodynamica]

Ello all, would anyone be able to access and post the wiring diagram for the horn circuit?

Thank you in advance

[GiveMeABreak]

Here you are Graeme. If the alarm is going off repeatedly, then probably time for a replacement alarm ECU as the internal battery is likely end of service life.

[aerodynamica]

Hi Marc thanks. No issues with the alarm as yet I only need the circuit for the horn itself as in the diagram for the horns, any relays used, location of earths and the switches i n the fixed center steering. I think the above plan is for the I/O for the alarm system as it connects via the BSI. I see that the horn is one of the outputs but I'm simply needing the horn circuit itself.

[aerodynamica]

Now that you mention alarm going off all the time - is this a known fault to expect in time to come? If it does that will it still turn off with the ignition key?

[GiveMeABreak]

It will, but isn't very neighbour friendly when it starts playing up. Given the age, these can start to go wrong anytime about now because of the service life of the battery.

The diagram above is the only one for the alarm system. They don't provide anything for the internals.

[aerodynamica]

Thanks, isn't there a diagram for the horn on its own? The reason I wanted to check it is to fit a different horn to the factory one and I wanted to see what the connections were and if it used a relay. I can work it out by inspection though - just like going in with info if it's available.

As for the alarm, is it possible to disable it and still lock the car?

[GiveMeABreak]

Without removing the alarm wiring, module and reconfiguring the BSI you can't disable it. But you can disable the alarm by locking the car with the physical key and not the fob.

No other diagrams Graeme.

[wheeler]

Not sure here but is the OP not talking about the actual horn (the one you toot with the button on the steering wheel) rather than the alarm siren?? That above is the for the alarm system not the horn diagram. Maybe im reading this wrong?

[GiveMeABreak]

[GiveMeABreak]

Thanks - yes I was referring to the alarm siren - Richard - I've replaced your image with the Hi-Res vector.

[aerodynamica]

That's the one Richard! I am installing an air horn and wondered if there was already a relay in the circuit. There appears to be within the component PSF1 - whatever that is.. but I think it will be able to drive the air horn compressor. Might have to lightly uprate the fuse F2 depending on what it is rated at currently. Failing that I'll use the output from the PSF1 relay to drive an external relay.

[wheeler]

PSF1 is the under bonnet fusebox (AKA the BSM).
The horn output is on pin 3 of the 28 way brown connector. And yes the relay is a non replaceable integral part of it.