Hi guys i recently have been trying to repair the horn in my 1989 V12 XJS. After discovering the previous owner had installed a novilty horn I purchased a orignal xjs horn from an itentical model.

I need advice on wireing it in as at the moment the Jag has to wires (red & black) which i know is positive and negative but the replacement horns have one yellow and green wire showed in the attached photo. How it i wire it up as im not an expert

 

Well it is just a switch, so it really should not matter how it is wired.


Also. I don't know if you attached the wrong photo, but those wires as absolutely purple and black, not yellow and green.

The assumption then would be that black is ground, and a check in a 1992MY diagram confirms black as ground and purple with the black tracer as power.

 

Hi thanks for the reply i upload the correct photo but do suffer from slight colour blindness. So would i connct the wire to the red or black one in jag?

 

Yeah I didn't want to just assume and be like "hey man are you colorblind or something?"

Anyways, the one on the bottom in the image that is cut off is purple, it feeds to power. I am assuming the black on that is further up in the picture is green to you because it is darker and it should be ground.

So with your current setup that would be black to black and red to purple(err yellow?). The one on the bottom and furthest to the left on the picture goes to red power source and the other is grounded using the black wire.

Again it should work either way, they are just completing the circuit. They still follow a color though because a cars electrical system would be a very confusing place if sometimes it adhered to color coding and sometimes didn't. If that makes sense.

 

Thanks again gor your reply,

It is just one single wire instead of 2 this is what's confused me.

 

Hear is a better picture, as you can see there is only one wire to connect to the jag?

 

Dave, you should find that each horn has only one terminal on it. The wire you have, purple and yellow, goes onto the terminal on each horn. Why you have two wires on one connecting plug is because the feed wire piggybacks from the first horn and the second wire goes on to the second one, thus connecting them both to the live feed. So the wiring when finished should go:

Loom feed to first horn, first horn to second horn. The feed to your old horn is the loom feed that needs to be connected up.

The horns are earthed, to complete the circuit, through their fixing bolts (so no second wire needed in this setup). Make sure you clean up the horn brackets and the body panel where they are fixed, to bright metal. Test the horns, and if all well, spray over the fixing area with some white grease, or smear it with grease, to stop it rusting.

Greg

 

ohhhhhhhhhhhhhhhhhhhhhhh

what an odd picture. I TOTALLY thought this topic was on the horn buttons. I have NO idea how i misread that and continued to think that picture was of the switch, maybe it was because the wiring colors purple and the angle you held one bracket at look like a black wire, which is right.

In the other picture is is really obviously the horns and purple has a yellow tracer on it.

Yeah you just need power, the horns ground themselves by being bolted to the car.


So sorry I probably confused the hell out of you

 

Haha yes u did!! So i connect the red wire to the horns and by bolting the horns to the car i dnt need to do anything with the black wire? Also is there a way of testing the horns with a car battery to double check they work?

 

Do you mean the old aftermarket horn system had two wires going to the horns?

If so, find out which of these two wires is live by having someone press the horn button (ignition on) while you place a test light or a meter on each wire in turn. The one that lights up is the live feed.

Connect this live feed to the push on terminal on the replacement horns using the piggy backed wire in your pic. Tape off the unused wire.

You can test the horns by taking them to the battery with the piggy backed wire connected to the push on terminal and touching that wire to the positive terminal while holding a cleaned up metal surface on the horn bracket to the negative terminal.

Greg

 

I was just curious and had to look. The horns on my car are inoperative and I really don't care!! Brake, steer or accelerate in lieu of a toot is my motto!


However, yes, you can apply power directly from a battery. But, in these days of fussy electronics, use on that isn't connected to a car. And, durn I'd say disconnect the one in your XJS, but that would blank out some memory stuff.


If you have a battery charger, that can provice the needed volts with no risk.


Just guess and touch the wires. if wrong, the quick short will not hurt anything.


Reverse, the hook up, it should toot. Now you knolw which is which and hook it to the Jag wires and if the rest of the circuit is OK, you have toot capability.


Have fun with the electrickery.


Carl