Having trouble with my horn if anyone can help. I've got so far but not sure what next. I've put power to both horns to confirm they are working. I've got 12v to the brown wire and green wire. I've put a jumper from the brown to the pink and yellow and the horn sounds. As I'm on my own I can't press the horn to see if the signal wire is going live. I've just bought a new relay that I'm going to fit. I tried earthing the wipers under the column out as suggested by Greg but the horns didn't sound. Only thing I can think of is the horn pad. Does the centre contact need to be in permanent contact with the horn push rod? Any other suggestions 🤔

 

Brinny
Somewhere on here a few weeks ago i posted the horn circuit diagram. One thing to try is the frontmost fuse in the LHS fuse box under the bonnet. This fuses the aux fan, but also the horns - fact that is not stated anywhere in Jaguar manuals.
The horn circuit (as in the horn relay trigger circuit) should be live right up to the wipers and the horn button, pressing the button earths the circuit trips the relay and makes the horns sound. If earthing the wiper does not cause the horn to sound, ignition on, then the relay trigger circuit is the problem - pressing the button does no more than earthing the wiper should. If you are on your own, you can still check if the wiper is live with a meter or a test light, it should have 12v ignition on. If it is not live, then that is the part of the circuit to investigate. Start with finding out if there is 12 going into thew relay c#trigger side, ignition on. If not, investigate that part.
If no 12v going into the relay, then obviously, no 12v going out of it to the wiper and the earth side.
Separate issue, the horn side of the relay should have 12 v going into it.

 

Hi Greg, I've two wipers one with a purple wire which has 12 volts when ignition on. A wiper with a black wire (earth?) Which has no power ignition on. There's us 12volts around 2 of the relay connections when ignition on.

 

Just earthed the purple wiper again and horn sounded

 

Great, so remove the wheel and look at the bits in the column.

 

Took the wheel off and fully extended the column and it briefly worked. Now nothing. Don't fancy stripping all this lot down. Another overcomplicated feat of engineering for something simple . I hate this car!