Horn not working ?!

[Jinxy]

Hello, my horns is not working. I replaced the steering wheel and horn as it was really grubby when I got the car but I’m not sure if it worked before that as the car wasn’t on the road for a few months after that. I’ve checked the  connections and that all looks fine. I can’t hear a clicking noise when pressing the horn with the ignition on so I’m assuming the relay is knackered. I know there are relays under the dash but does anyone know where it actually is? I will check the contacts tomorrow and to see if the horn actually does work in the mean time. Cheers 

[Breezy_Pete]

Horn relay is built (soldered) into the Onboard Supply Control Unit above the accelerator pedal. I doubt it's that though.

 

Check fuse 40 is present,  intact, not loose and has clean connections.

 

Possibly a switch/input problem following the steering wheel replacement, rather than anything on the output side, if you don't hear relay clicking?

[Jinxy]

Just checked the fuse and that’s fine even tried another just to make sure. 

[Breezy_Pete]

I think it might be one of the output tests you can run on that module, if you have VCDS/VCDS Lite (registered).

Edited 12 February by Breezy_Pete
Sp

[Jinxy]

100% not getting a relay clicking noise when pressing the horn in. Also not getting any power at all to the horn it self. I’ve checked and tested the fuse again thats all good. Had the horn off and that all looked fine also. Kinda of stuck now. 

Also wasn’t able to do a output test on the horn as my vcds won’t let me use any other module for some reason.

[AGFalco]

 

10 minutes ago, Jinxy said:

Also wasn’t able to do a output test on the horn

 

Did you test the horn when it was off the car?

 

Thanks. AG Falco

[Jinxy]

no I haven’t tested the actual horn it’s self yet but I’m not getting any power down there anyway. 

[Alasdair1]

Not sure but the horn power supply might come from a spiral cable spring in steering wheel that does the airbag as well. If its failing the horn stops or the airbag light comes on. 

This might explain lack of power to relay and horn etc. Not sure how to check it but if messing about disconnect battery and leave for a while so theres no chance the airbag goes off.

Alasdair.

 

[Breezy_Pete]

^ Yes, but just the input signal that tells the control unit that horn sounding has been requested, as opposed to a power supply for the horn.

It's what I would suspect too, given the lack of any relay clicking, and the OP having mentioned doing something with steering wheel.

[Jinxy]

Update the air bag light doesn’t show up during ignition cycle. I’m not sure if that’s anything to do with it? 

[Jinxy]

EDIT* it is coming on now

Also when I purchased the car the front did have some damage nothing major but it could’ve set the airbag off. Would that have anything to do with the light not coming on and why the horns not working? 

Edited 13 February by Jinxy

[Alasdair1]

I had an old toyota lucida with air bag light on. It was the spiral cable that was faulty but the horn still worked. To get it through an MOT I managed to disconnect the crash sensor unit which turned the light off during ignition and afterwards. I disconnected it as mine was going to be very expensive as it was a Japanese import vehicle. If its the cable I think they are £50-£80 for a fabia. I think they are called clock spring cables. The airbag part of the cable  probably failed before the horn and whoever had it before may have disabled the airbag system hence why the light doesnt come on

Alasdair