I have a 1987 XJS Coupe. I have searched all of the posts I can find and Kirby Palm's book re: horns staying on and I still can't figure out what the problem is.

I was told that if the steering wheel isn't tight and the hex shaped nylon piece that is attached to a copper rod isn't tight that this could be the cause. I am stumped. I looked at mine today and the copper rod and the steering wheel were both tight. I loosened up the rod and took it out at it looks like brand new. Without the horn pad on the steering wheel if i use the telescoping ring and slide the steering wheel in, even just a little, the horn blares. If i extend it all the way out and locks it, it stops. Thats where I have it locked now and then the horn pad works to activate the horn.

Any ideas where I should look next?

Thanks

 

Horns work by the circuit being live all the time and when you press the horn it earths the circuit and makes the horn work. You have a short in the column. If it is affected by whether the wheel is in or out on the adjuster, that is a good pointer to where the short is. Sadly, it could well be in the insulation inside the column, as when the wheel is fully in, the horn rod with the nylon nut is in a different position within the column. If this is so, a columns change is the best solution as th insides are not get-at-able. A column chnage is not that hard, actually.

It is worth removing all the column trim around the rear of the wheel though, and seeing if anything is grounding when you move the wheel.

But before you do that, have a look above where yuor shins are, by relmoving the under dash panel. You will see a couple of copper wipers running against the column attached to loom wires. See if one or other of these is touching anything.

Greg

 

Thanks - I will check it out this weekend

 

You can read my many funny (now - embarrassing then) threads on this very subject.

Quick fix is to snip the wires at the horns, but that is unsafe if you have to drive any distance.

 

In the picture I noticed these parts (#2 & #3) further down on the steering column having to do with horn earth contacts. Has anyone replaced these yet?

 

https://www.jaguarforums.com/forum/x...column-120046/

I think I'm on the right track . . . hopefully it warms up over the weekend so I can check it out.

 

Those are the 'wipers' Greg was mentioning


Cheers
DD

 

the mounts for these can become loose and cause a short or open circuit resulting in horn problems

the parts shown above are available brand new from jaguar for about $10 each , or less


they are fiddly to refit, but it can be done, as i have replaced my own

this will no doubt be your issue with a continuous horn

BB

 

My bet would be the spring that connects the rod running down the column to the lower wiper. If you pull the connector out of the lower wiper does the horn stop?

I had a similar issue with my horn. Check out my blog, it has the first repair, and how to disassemble the column. As usual with these it failed again. I ended up removing the rod from the column and running a wire (silicone insulted) down the column.

 

Wow - that looks way beyond my skill level. I can't really see what's going on down there when I crawl under the dash. I don't even see anything to disconnect from the wiper.

I think for the time being I am going to leave the steering wheel ring locked as far back as it takes to stop the horn from honking and re-visit this when I have more time getting to know the car.

 

Did you leave the nylon hex beyond the steering pad and just cut off the rod and solder a wire to the back of that? If so, where did you solder the other end of the wire?

Thanks