Hi guys from 2 weeks I'm proud owner of Xj40 3.2 1993 everything is working absolutely fine apart from horn horn when I bought the car was showing on dash board short circuit light FUSE 2 it was horn fuse (broke) I replaced it and as soon I put new fuse in horn turn on and is constant on. 🤔 Any ideas?

 

Please use punctuation. I would look at the ground wire side of the horn circuit. Or maybe there is a problem in the steering wheel at the buttons causing them to stick. If you dig into the steering wheel be sure to look at how to disable the airbag. At least you can unplug the horns temporarily if you need to. Good luck.

 

Hi Karol1987,

Welcome to the Jaguar Forums! It's great to have you with us.

First of all, do you have any warning lamp that might indicate that your security system is activated and causing the horns to sound? In your '93 there may be a switch to disable the security system under the center console armrest lid. I think the headlamps will also flash if the security system is triggered, but this may vary by market.

It is perhaps possible that the horn relay is stuck in the closed position. This relay is inside the relay module behind the right headlamp, which I think I recall is protected by a black plastic case. A very common issue is cracked solder joints on the circuit boards of these modules, especially around the large relay pins. I don't recall a horn relay sticking in the closed position, but it's certainly possible.

Here's the horn circuit schematic:


You can see that the horns can only sound if they receive battery power via the Yellow wire from the horn relay (Y color code), or that wire is shorted to battery power somewhere else.

Not shown in the above 1993 schematic but shown in the 1991 schematic is that terminal 86 of the relay is connected to terminal 30, so that end of the relay coil receives battery power from the same source, 68, which is Fuse B6 (15 amps) in the fuse box at the base of the right A-pillar.

The relay coil is activated either by a horn switch in the steering wheel connecting to Logic Ground, or the Security System ECU grounding the Green wire with Blue tracer stripe (GU).

With the above information and a volt/ohmmeter, you should be able to test for shorts and the source of the voltage to the horns.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don