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Am I misunderstanding Horn 101 slightly? I understood the horn acts with a floating ground between the pusher on the steering wheel and the horn relay in the engine bay. However (and keeping in mind I took this column apart a little while ago`) the cooper barrel inside the steering column and the connection at the based of the column both show a constant earth. An I missing some isolating elements in the column assembly then? Have I left out a sheath or cover? Big solid earth signal all around.
When pressing the horn pad, which is Grounded/earthed by these screws from the back of the steering wheel, it makes connection through the probe (in the center of that nylon bolt) in the center, below;
At that point the ground complete, when the connection in the horn pad, touches this brass rod, which makes connection with the wipers on the column.
One must make sure the sleeve surrounds the tip inside the column or again, no connection happens.
Until all these all coincide, the circus is incomplete, and no horn sounds.
(';')
Yes, that probe (brass rod) can be an annoying little tosser. Mine was shorting on the inner column such that when turning the steering wheel, the horn sounded.
Basically, it made the car undriveable!
Last edited by redtriangle; Mar 30, 2025 at 09:07 PM.
Removed and re-examined the cooper brush and found i used a rivet to hold it to the bracket at some stage so replaced with nylon bolt. so then the cooper in the colum and the brush appear to be safely floating as an earth. then the grounding returned when i plugged in the purple-black wire to the relay, so i tested the p-b wire end to earth and it also seems insulated from the common earth. finally arrive at the relay where the ground pin 31 seems to be firmly earthed for some reason.
took apart some of the wheel and feed a probe wire in but could not find an established point of continuity to brush. sure i had one before. the cooper rod on this case took exactly like the one in your picture.
Aden, all these you mention to this point should be grounded to earth.
That brush/wiper should NOT be connected with insulating nylon bolt but hard fixed to some commonly grounded body part.
Mine is riveted to the outer column, which is firmly grounded to the body, which itself is grounded to the -battery post with a 3/8 inch bolt.
The only part of this system to have +power is the rely itself. Everything else in the horn circus (yes I meant the 3-ring kind) is grounded to earth.So that when you push the horn pad in center of wheel, you complete the Ground connection and power can travel from battery round Robin Hood's barn through steering column and finally wander off to ground the rely, which then closes to send +power to the horns.
So essentially, you're merely grounding the rely which is powered directly from the battery.
It's Anything but straightforward, Needlessly complex, not the Least bit logical, but what else have we come to expect from Classic Lucas-wired Jaguars??!
(';')
That is what i would expect but doesn't seem to be what is happening here. Feel likes there is earth to spare where there shouldn't be and none where it is supposed to be found. Got tired of trying to work inside the cain so taken the column inside for a look. some really good older posts on the forum about these issues too which i have been looking at again.
i will never remember which goes where when putting back in
So as i understand it i should be getting a clean steady continuity signal between the top of the road and the cooper ring / cooper brush section as the connection at the horn sends this floating earth signal all the way to the horn relay. At best I am finding intermittent continuity and not sure what else to extract.
Here's the detail shots, the length of the cooper rod and the tip of coppery contact (or not) deeo in the steering shaft. no matter how forced down she is I don't get a continuity with the cooper ring.
measure of the cooper rod of doom measure when the rod reaches the contact node (inner rod)
then the macro photography details looking down the shaft of steeringness to the node of cooper probyness itself looking down the shaft of steeringness to the node of cooper probyness itself looking down the shaft of steeringness to the node of cooper probyness itself looking down the shaft of steeringness to the node of cooper probyness itself looking down the shaft of steeringness to the node of cooper probyness itself looking down the shaft of steeringness to the node of cooper probyness itself
You should also "burnish" the ring on the column where the metal "brush" pushes against. Also... while you have the column out, now is the time to replace the electrical part of the ignition switch. It WILL require replacement at some time in the future.
Yes! As Bill mentions, perhaps a good clean of the contact surfaces would be useful.
I notice the column looks a bit dirty, probably the wipers aren't much better.
GREAT shot of the innards of the shaft btw! Shows plainly what's down that rabbit hole.
(';')
and just in case you thought you'd seen too much already this image again with a rough impression of the platform (in green) which is suspended in the column centre and one node (ned) a bolt fused to the cylinder's side just fractionally above the platform. the 'stamen' cooper probe sits up rigidly from the centre of the platform about 2.6 inches.
Aden, I've never had my column this far apart! Never saw the need personally.
Ya never know with a Jaguar, some of the bits seem to have been engineered to last Forever while some about 15 minutes; hazard/turn/signal parts for example.
(';')
"can i then strip this guy down any further or is this as far as a surface amateur like me can go before needing weltering and an engineer?
Yes is the answer The inner column can be withdrawn from the collapsible outer by removing the circlip at the bottom of the whole unit.
Naturally, there is no guidance to this exercise in the shop manual.
As I recall, it is spring loaded at the bottom, and include several (?) shims or washers to set the tension.
This brings you to the interesting part (after withdrawing the inner), there's a small spring set into an (internal) plastic collar with aligns with the outer Cooper ring and this is the source of continuity between the ring and the internal rod.
I guessing this is where your problems is as if there is no grounding, there will be no horn operation.
Now that I am reminiscing, I recall there's two needle bearings (top & bottom) which obviously get no attention during the life of the car, and may need servicing, and very worthwhile task now that you have gone to all this anguish of removing the entire column. I used copper grease as a lubricant.
Please note I am referring to the Series 1 XJ6, the S2 maybe different, but I don't think so.
I have added schematics from the Jaguar XJ6 parts cattle dog below . Note that the plastic bush/collar referred to above is shown on the end of the brass rod.
Hope this helps.
Last edited by redtriangle; Apr 4, 2025 at 01:35 AM.
not that it seems make sense to me but the second guide hole brush thing further down the column which is earthed to the column has continuity with the top fo the probe ........
hole with the horn brush at left and other 'guide?' brush at right
many thanks for the diagram. removed a retaining ring and a fairly high powered spring and several washers emerged and a cap section. So might be a tiny bit different from the diagram as at this point i don't have the inner column free, there is still a rim with a triangle indent holding it in place (see image).
got there. not sure if i am any the wiser but have that pioneer feeling of going boldly (or blindly) where no man has gone before.
here are the crime scene photos ;
force this bit down pops out popped out wide shot rings out extended rings within rings rubber ring cooper ring wide shot rings within the cooper ring, plastic two piece rings within the cooper ring, plastic two piece, rusted spring in a screw hole the offending interior probe / node the two rods of the horn system the plastic tripod bracket that prevents contact with the outer rod
Horn Steering Column Trigger
The inner column can be withdrawn from the collapsible outer by removing the circlip at the bottom of the whole unit.
