my horn doesnt work,
in fact when i got the car someone had installed a button below the steering wheel instead of the centre push button on the wheel.
I've pulled apart the steering wheel and found the two brass tubes (lower and upper) in the centre of the steering column. The upper tube slides over the lower tube and can be removed when you remove the steering wheel and steering wheel adjustment mechanism. The horn button has a brass centre contact for the upper brass tube and then a wire to earth to the steering column.

The lower brass tube has no continuity to ground so i figure that must be for the power. I've also found the purple and black wire that supposedly operates the horn but it does have continuity to ground. For the life of me i cant find out where the brass tube goes and how it gets power to it. I've stopped short of pulling out the column, it looks like an annoying job and i thought i would stop by here and see if anyone can help me physically locate the bottom of the lower brass tube/ where power goes into the horn?
The manual has an exploded diagram of the column and shows the lower brass tube but doesnt label it or show if its possible to get to it. I cant seem to pull it out either.

Thanks
Glenn

 

did you take any pictures of the brass tubes?

 

Your steering column is a straight forward operation to remove, remove the speedo & tacho first to access the top bolts.

If your car is the same spec as my 73 series 1 you will have two purple/black wires connected to the steering column, totally unrelated to each other.

The top wire goes into the ignition switch harness then a blanked off wire for the US market(some sort of alarm buzzer.)

The bottom wire goes to the horn push(other end is at the horn relay), see yellow arrows in picture.(disregard the red arrow, it was for a previous post but only pic I have the two purple/black wires in it)

 

Far more detail than I can offer. But, for whatever it is worth :


1. The gadgetry in the column is not power direction. But, a means to complete the ground leg of the horn relay.


2. In my car there is an in line fuse in the RR corner of the engine bay. Battery here in my LHD car.


3. At the base of the steering column a spring like shoe is located. It is a means of connecting a shaft that rotates to a part that is still to complete the ground leg. Dirty, no continuity here???


4. My Jaguar's "toots" are inoperative. To me a bottom of the priority lit item.
to those who have MOT, of much more import...


5. Have a look at the PO's bodge. What circuit does it complete? Ground, I suspect.


6. IN Jagaurese, key on is a must in a lot of things!!!


7. Thusly, an ignition switch that is "healthy" is a must. Don't ask....


Carl,


Carl

 

Cracked it!
Thank you all for your replies. It was the usual problem, corrosion/ poor contact.
o1xjr you helped me get a picture of what to look for and a good push in the right direction. I need a good mental picture sometimes before i feel comfortable diving into something.
Jag Cad, points 1 and 3 were spot on. power goes through the purple black wire to the brass tubes that are insulated from the remainder of the column, had poor continuity there.
The PO had installed a very simple; battery +, to button, to horn, to Earth, system to replace the horn and left all the original wiring in place. It actually would have been slightly easier to clean the original rather than put in new wiring but wiring is still witchcraft to me so i kinda dont blame them.

I dont know what the other earth point is for, it has no wires going to it. i cleaned it up anyway while there.

The brass horn finger and the bit it contacts on the inner steering column were corroded i cleaned it with degreaser and sanding paper (that came out very dirty). now it works just fine. I bent it out of the way to clean the brass thing inside the column, if youre doing this, leave it in place because it was a bit tricky to bend back into place.