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Triumph TR6 - Quirky Horn

Having some problems with the Horn.
Seems to only function with the ignition off.
Discovered the hi note had a broken lead so took it off and have ordered a new one. Still the low note only functions with ignition off. Have checked grounds all seem ok. How do I check the relay? What else could it be?
Thanks. Ian
Ian Kinaid

I have the same problem you describe I hope we get some help I am beginning to think it is ignition switch related but am not sure, mine will always work key out if the center of the ignition switch has popped back to where it belongs. It will work once in a while with key in and in the on position baffles me I rewired when I installed a radiator shroud and have not had the time yet to reexamine it.
Keith 72TR6
KBD Dixon

Ian and KBD,
Time to take your wiring harness apart, clean the
connections and coat with dielictric grease.
What you are discribing is classic grounding fault.
You're cars are over 25 years old, time to give them a once over.
Christopher Trace

Ian and Keith
Both of you talk about the ignition being on or off.
Your ignition switch should have no effect on horn operation regardless where the switch is ( as a side note it sounds like you have a problem with the ignition switch Keith).
So maybe I am taking a long shot here but do you have the horn Purple wire connected in correct location at the fuse box?? The top fuse White wires comming in on the supply side ( 1 of them from the ignition switch)...Green wires coming out the feed side. The second fuse down has one large brown wire supply side (directly from the battery) and 2 purple wires going out the feed side, one of these purples being the feed to the horn relay. This is the correct setup and as you can see this is a direct connection to battery + side and has nothing to do with the ignition. No offense given (and hope not taken) here guys but like I said, you both mentioned the ignition switch.

So if the above is correct then lets look at the wiring to the relay. From the fuse box to the relay is a purple wire to C2 of the relay. Your horn push is connected to W1 through a Purple/brown wire....NOTE there is a butt connector inline here at the steering column wiring harness....DIELECTRIC grease!! From C1 of relay u have a single purple/yellow going to the horns. The P/Y goes to left horn in a spade connection with a second P/Y coming out of this spade going directly to the right horn. The horns have their mounting bolt as the ground to chassis.
Sorry got a little carried away here...but yes u can check the relay. Simply disconnect the C1 and C2 wires from the relay and touch together. If u got a loud noise from the front of the car...replace the relay or look at the horn push button. (I assume your horns are working with plenty of DIELECTRIC grease at the contacts as well as the ground of the horn). The replacement of the relay is easy but first have a close look at the horn push. This is definitely an area that can offer intermitent operation. Look at TRF catalogue green book page/items... 319/EQ21 and 22.....clean and apply DIELECTRIC grease. Check the butt connector coming out the steering column as mentioned above (EQ21 wire). The horn push has the outside ring springs as the ground contact...clean and apply DG!!
My money is with Chris on the bad connection! Relays are not intermitent...bad connections are!
Good luck and let us know your results.
Rick C
Rick Crawford

OK a little more info.
The ignition switch look s alittle different from the one in the Bently shop manual. 1970 in dash switch.
wired as follows.
1.RW 2. NW 3.W 2 leads 3. B wire which appears to run to a condenser attached under the dash.

Now when I take ignition switch off key lock and start with a screwdriver, horn works, however with ignition switch still unattached as soonas I unlock the steering with the now idependent key lock the horn doesn't work. weired....
Ian Kinaid

almost certainly as Chris and Rick alluded to the grounding issue.
When the key is moved from 0 position & the steering lock dissengages so does the ground link.
with horn press switch taken off steering wheel
ran wire from spring switch to ground under the dash with swith in 1 position beep beep. now having trouble finding where steering column horn ring runs to ground.
I would have thought that the steering column would have ground simply from it's run through the car.
Question is does the horn ring have a separate ground?

nuts.... Ian
Ian Kinaid

OK, well I took the steering wheel off to find where the horn connection is. Found that is appears to be
an old retaining ring is the culprit. apparently the 3 prong retainer ring provides the ground to the press horn switch. 1 prong was broken off and the other two were not making contact.
Ian Kinaid

Still not sure why you refer to the ignition switch. As far as I can see from any year (even back to TR250) the Horn has nothing to do with the ignition switch. I think the ignition was tossing up a "red hearing" for u with a flaky ground in the horn.
Ian if you refer back to my last posting you will see that I told u "The horn push has the outside ring springs as the ground contact...clean and apply DG!!"
The steering cloumn does indeed have a grounding strap and does not rely on metal being bolted to metal. If u look at the steering rubber couplings u will see a ground strap going from one side of the coupling to the other (bolt to bolt) and then at the base of the steering shaft a ground strap to the steering rack. Also what u refer to as a condenser I think u will find is actually the dreaded ignition buzzer that I have disconnected...I hate those things!! As u can see Ian, your problem had nothing to do with the ignition switch.

Keith..ignore the ignition switch and read my last post and/or go strait to the disassembly of the horn push button.
Rick Crawford

The ignition key has everything to do with the horn. Or at least it appears to do so on my TR. The horn works when the key is not in. Once inserted all is still okay. But once the key is turned to the on (and starter) positions ... nothing. Even when the key is turn back to the off position, still nothing. When I take the key out. The (freaking) horn works. This makes may rolling honking efforts rather exciting.

I'm certain the evil Dr. Lucas is having good hearty chuckle over this dastardly ploy.

Rick is far more knowlegable than I regarding this quirk. It is without a doubt a grounding issue.
What I think does happen regards the ignition switch or rather the steering lock is it appears to help provide a more direct ground when lock is engaged diverting your attention from the real culprit which is a contact from the steering wheel itself to the hub or boss. The horn push does indeed have a ring spring that contacts the steering wheel to horn push. The problem which I think I had was the two retainer clips that hold the slip ring in place also appear to provide ground to the steering wheel itself when the base of the steering wheel contacts these reatainer clips. Anyways when I ensured a better contact with these clips and base of steering wheel I seemed to enable the horn under all conditions albeit requiring a firm push to activate horn.
Ian Kinaid

You have it dead on. The spring ring is the ground. I agree with you 100% on the key lock aiding in the grounding issue for Bryn. As soon as he turns the key (unlocks the steering column) then horns fail. When I look at the electrical schematics, the ignition switch does not have a ground. So Bryn it is NOT the ignition. For sure, when in the lock position (ignition off) the bolt (steering column lock) goes into the steering column inner shaft which happens to be the same hunk of metal that the horn uses as a ground...the ignition assembly is bolted to the body... Voila...ground...the horns work. This is NOT the way Coventry planned the ground for the horn!!! After all..we do need to turn the wheels a little while driving. Like I have said before Ignore the ignition switch it has nothing to do with the horn. Read my post of Aug 19th and Ians of Sep.14th. Simply put Bryn fix your ground problem. I will put money on it that it is the ground strap at the flexible coupling (dirty or broken wire). Bryn I do not think your problem is up at the horn push button. If it was then the key lock ground thing would not give you horns.
Let us now what you find.
Good luck
Rick C
Rick Crawford

Ian And Rick:

Grounding it is. After much puzzling trouble-shooting, I found the broken ground wire down by the rack and pinion. I had the steering wheel end completely apart and tested thoroughly but could not find the fault. Fixed the wire at the other end and all is well. Thanks.

NB: It's fall and finally I have the beast running reasonably well. clutch works, gears spins, differential quiet, I can find reverse and the horn sounds when required. BUT, today the thrust bearing went. It makes an awful noise when I step on the clutch although it still appears to function. Enough already; I'll wrap it up and wait 'til the spring.


Better now than the first beautiful day of spring. At least that s what I am told
Don K

Bryn you can sit in your garage and play with your horn this winter:)
not wanting to sound like "I told you so" (seriously) re-read my last 2 sentences and you could have been out driving her sooner.
Just curious, but do you mean the throw-out bearing?
Rick Crawford

Beep Beep.
Just because I didn't have a horn doesn't mean I wasn't out driving. I do a very good road-runner impersonation, or so I am told. I will take your advice to heart next time.
Re: thrust bearing. Yes, it is the throw out bearing. I made an adjustment in the master clyinder pushrod length (lengthed by 1/16") so as to get it into reverse easier. It was working like a charm but, as many TR drivers will atest: for every action there is a catacylsmic reaction. No more throw out bearing.

Goog think it is the end of the bug season. Maybe it is just me, but it seems there are more idiots out on the road when I am out in the 6. It is kinda like driving a motorcycle...invisible. Maybe I am just being to paranoid.
Well instead of competing with your cars horns this winter, there is somthing else you can do....bummer.
Rick C
Rick Crawford

Rick your not alone
i too wonderd the same thing
people must think an old car can,t be going that fast?
so i,ll cut in and more than once the car a head drifted repeatly onto the soft shoulder. oh well

This thread was discussed between 14/08/2002 and 11/10/2002

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