Ian Cooper Posted January 6, 2021 Report Share Posted January 6, 2021 Hi Folks. I've refitted the bonnet with new head and sidelights after paint and I have a long, single black ground/Earth wire with a 'banjo' connection emerging from the harness. As the bonnet was removed by the paint shop (years ago) I have no idea where this wire is connected, the W/S manual diagram does not help. Anyone any ideas please?? Thanks Ian Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 6, 2021 Report Share Posted January 6, 2021 A bit blurry, but the black wire comes out the loom and bolts onto the quadrant mounting bracket. The silvery bolt in the picture. Doug Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 6, 2021 Report Share Posted January 6, 2021 Possibly - possibly - to the bolt that secures the horn bracket to the inner panel behind the nose. I have a ring connector on each side to this point to earth the horns, but I know I've added one myself and whilst the other was there originally it might just be my car only. However, connecting it to any good earth point that it reaches won't do any harm. Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 6, 2021 Author Report Share Posted January 6, 2021 Thanks for responding. Tried the horn mounting bracket and weirdly the horn sounds when I turn the ignition key??? Ian Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 6, 2021 Report Share Posted January 6, 2021 In which case, it's not an earth then... don't connect it to anything else until you know where it comes from - it may be a home-made power source for spots or the like. Can you test it (use a bulb or meter) to see if it really does power up when the ignition comes on? Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 15, 2021 Author Report Share Posted January 15, 2021 Finally got back onto this and taken the steering wheel off. The horn connecting plunger/horn brush is completely missing and it looks as if someone has been filing the boss so I believe it's been earthing continuously, which I'm pretty sure would account for the horn sounding when I turn the ignition key, do you see this as the correct explanation? I'm thinking of applying a thin coat of epoxy resin to the 'filed' areas, as an insulator, and replacing the missing plunger/horn brush. Any thoughts or suggestions/tips/experiences I can learn from?? Ian Link to comment Share on other sites More sharing options...
NonMember Posted January 15, 2021 Report Share Posted January 15, 2021 I don't see any problem with the epoxy idea, but it shouldn't be much use, either. There should be plenty of clearance from the hub to the horn contact ring. Also, the horn should be powered off the purple "permanent live (fused)" wire, so the ignition switch shouldn't affect it. I think you need to do a bit more digging on the wiring. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 15, 2021 Report Share Posted January 15, 2021 How does your horn work, if there's no pencil? It completes the circuit, and is insulated from the rest of the steering column by the plastic outer. If the horn works at all, then power is getting through somewhere else, and the circuit is being connected somewhere else. The steering wheel rubbing won't make any difference - is that filing, or just wear? - if the steering wheel has been left out of the circuit already. Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 15, 2021 Author Report Share Posted January 15, 2021 At first I wondered if it was rubbing but the marks would be radial and these are straight so someone has been file happy. The brass contact strip has also been filed from square to roughly semi circular, so I have no idea what that's all about. Guess I need to to try and work out what's going on and try to get back to what it should be. It would be really helpful if there was a harness drawing rather than a circuit drawing. Ian Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 15, 2021 Report Share Posted January 15, 2021 The horn circuit is always live; pressing the horn push completes the circuit to make the horns sound. It should sound any time, not just when the engine is turned on, if the contact is made; you can test by bridging the horn ring to the steering column with a short length of wire. Is the brass horn ring still connected to the purple wire? Find out where that goes; it should keep to itself and not be spliced into anything else for the length of the column. Has a PO removed the horn pencil and fitted a remote switch anywhere? Link to comment Share on other sites More sharing options...
NonMember Posted January 15, 2021 Report Share Posted January 15, 2021 Also worth noting that while the Herald and Vitesse have a simple wire from the horn ring to the horn, the Spitfire and GT6 have a relay in the way. The relay may even swap switch sides so that there's a ground wire to the horn rather than a purple power feed. Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 16, 2021 Report Share Posted January 16, 2021 Mine is as the diagram, the horns are earthed. The ground wire from the horn push operates the relay, which puts a live feed to the horns. Doug Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 16, 2021 Author Report Share Posted January 16, 2021 Hi Doug, thanks for the comment. Can I ask you where your long black wire, which emerged from the harness at the bonnet and has a 'banjo'/washer connection, is physically connected please? Ian Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 16, 2021 Report Share Posted January 16, 2021 Hi Ian, It's on the bolt on the quadrant mounting bracket. I put a picture up earlier on. Doug Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 16, 2021 Author Report Share Posted January 16, 2021 Sorry, I didn't put 2 and 2 together, it's brain fade from buggering about in a cold dark garage😁🤔 Cheers. Ian Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 16, 2021 Report Share Posted January 16, 2021 Ian, In those circumstances I recommend alcohol. 🤪 Doug Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 16, 2021 Report Share Posted January 16, 2021 Following the earlier post where by connecting it to the horn, the horn sounded, have you confirmed it's definitely an earth and not an aftermarket power source? Just checking... but I'm allergic to letting the smoke out of looms. Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 16, 2021 Author Report Share Posted January 16, 2021 It emerges from the loom sheathing with all the other wires and looks to be original, it even has original underbody seal on it. My guess was it was there to provide a 'Proper' ground/eath to the bonnet. Unfortunately I didn't remove the harness (the paint shop did way back in history) and I'm pretty sure they won't remember, thats the trouble with a loooooong restoration. It's long enough to reach either of the horn mounting brackets, but as mine's a Mk2 I don't have the quadrant brackets, as per your Mk3. I've discovered the main headlight switch is only making two positions so it's obviously not helping me to sort my gremlins, so what with a missing horn brush mystery wire and strange filings its proving irritating so the alcohol suggestion was a great idea (sod dry January). I may add a new horn relay to my next shopping list, just to be on the safe side! Cheers Ian Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 16, 2021 Report Share Posted January 16, 2021 Here's my Mk1; non-standard horns (off a Mercedes so they're loud, good quality and don't rust!) and bolted to the bodywork on the inside of the bonnet; bare metal round the bolt for a good earth then coated in Waxoyl. The black wire comes off the terminal to the top then loops round and is bolted in behind the panel with a serrated washer - it looked neater than under the bolt head on the outer face. Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 16, 2021 Author Report Share Posted January 16, 2021 Hi. Been looking through some very old pics and found these taken during welding. The long Black Ground/Earth can be seen hanging in 1812a (bottom right corner) and 1814a (upper centre to lower left). 1812a and 1813a show the main feed to the horns and a Black earth/grounds which also connect to the mounting brackets. This is what I'm trying to replicate but I don't have any reference for the other end of the 'Long Black Ground/earth at the centre grill (1814a), I assumed it was carrying Earth/ground to the bonnet but I suppose it could have been looped back to the chassis somewhere??? Ian Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 16, 2021 Report Share Posted January 16, 2021 If you can make out my wiring; the purple wire is the feed to the horn, but it was too short to reach the other; I just piggy-backed a second off it at the horn terminal, had no purple so substituted light blue, so power goes to one horn terminal on the left hand via purple and from that terminal, right hand light blue connection to the same terminal on the other horn, then the shorter black earth from the other terminal to the bracket bolt on each. The earth does not need to travel very far and certainly not back to the other horn as may have been original , but uses too much cable to be tidy.... Link to comment Share on other sites More sharing options...
Ian Cooper Posted January 28, 2021 Author Report Share Posted January 28, 2021 Hi. Just to round this off, in case anyone else has a similar issue, here are the conclusions. 1. The long black wire I mentioned, coming from the end of the harness, was indeed factory fit. It was, as I suspected, a 'Good' earth/ground for the bonnet and it connects to one of the horn mounting bolts (drivers side in my case). 2. The issue with the horn sounding when the ignition key was turned was due to the bulkhead solenoid being incorrectly (by me) connected (there was an additional small blade connection on the replacement solenoid. Using this connection meant there was no live feed to the 'Live' side of the fusbox until the solenoid was engaged. 2a. The horn push had a number of items missing (the 'pencil' brush and the horn push retaining clip) and there was evidence of filing to the back of the steering wheel boss and the horn push connecting strip. My explanation is that the steering column bushes were worn and that 'play' allowed the wheel to move sufficiently to short the horns ON, so someone (not me (historically)) had decided to increase the clearance by filing the boss, rather that replacing the column bushes. This doesn't look like it worked so I'm guessing they removed the 'Pencil' brush and horn retaining clip. I'm not convinced this would have silenced the horns but hey I'll probably never know for sure. I also discovered that the main headlight switch was broken, so that is now replaced and electrically I think all is now good, or will be when I replace the column bushes and replace the horn push. (horns are good when shorted with pliers so the circuit looks good). So hands up it was a brick that I dropped and some historical Hocus Pocus! Cheer Ian Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 28, 2021 Report Share Posted January 28, 2021 1 hour ago, Ian Cooper said: So hands up it was a brick that I dropped and some historical Hocus Pocus! Cheer Ian You were just being like me, talking out loud to get the problem focused in your mind before sorting it out. I do it all the time. The joys of being a Triumph owner! Link to comment Share on other sites More sharing options...
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