Horn sounds on full lock

[AndyG1972]

As the title says, got a 2006 Toyota Aygo and when I full lock the steering wheel (left or right) the horn sounds! Have replaced the clock spring (had to replace indicator stalk as bad anyway so thought I'd do two jobs at the same time - air bag light also flashed) Anyway, airbag light ok now and indicators fine but horn still sounds on full lock so can only assume there is a problem with the earth wiring in the steering column and it's being earthed when the wheels are full locked left/right.

Am trying to find a workaround as car is due MOT in December and obviously won't pass if horn is disconnected.

I was thinking of rewiring the section between the steering wheel earth and the horn relay. Can anyone point me to any wiring diagrams that might help and advise what colour wires i'm looking for. From what I've read the contacts on the steering wheel earth a relay in the fuse box under the bonnet so If I replace that run of wire then it should, in theory, solve the problem.

TIA

[flash22]

You need to break down the circuit - unplug the connector from the clock spring under the steering wheel use a meter in continuity between the horn pin and a body ground, and see if it still does it

 

Turn the steering wheel lock to lock using a wheel shuffle motion

the horn is fed on both sides of the relay by the same live the horn button acts as a ground side switch on the control side

KGB10 horn diagram.pdf

[AndyG1972]

Thanks Flash. I'm wondering if it may be quicker to just order a 12v horn relay kit off the internet and rewire the horn. Use the earth off of the clock spring to control the relay. Someone mentioned that on another forum but didn't give any specifics and didn't use a relay (which apparently isn't advised)

I don't really like the position that the horn is in anyway (as you have to remove the front bumper to service it which isn't ideal)

On the original clock spring that I have here in front of me it has two connectors, one has a single pin which I assume is the earth and the other has two pins (which go to the airbag - blue and yellow wires encased in a yellow shroud) A quick google search and I can see someone has said pin 1 is horn which seems to fit with what I see in front of me.

From the looks of the diagram you've sent the horn contacts earth themselves with the steering column itself and not via another wire? I think that the wire in the steering column which plugged into the other side of this clock spring was white which tallies with the diagram so am assuming I can cut that wire and connect that to the earth on the new 12v horn relay kit (to control the relay) which should aleviate the problem.

Does that sound about right??

[flash22]

Diagnose the issue first rather than complicating matters, I doubt the issue lays with the relay, the horn grounds through the column