SpitfireGeorge Posted August 19, 2023 Report Share Posted August 19, 2023 Hi Guys, Cannot get the horn to work and think it might be the relay, 50+ years old and very rusty externally. Horn relays are no longer available but I have a new 6RA relay going spare. Should this be wired up as per the std horn relay 1 power feed or should it be wired as per the O/D with 2 12v feeds? Cheers, Brett Link to comment Share on other sites More sharing options...
Pete Lewis Posted August 19, 2023 Report Share Posted August 19, 2023 only the one surely ive not seen a duplex feed on my OD realy any modern 20amp relay will work the horns ok Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted August 19, 2023 Report Share Posted August 19, 2023 (edited) Mine died and I replaced it with a modern off a Peugeot 306, I discreetly hid it behind the servo with the original relay redundant on the bulkhead. The horn button puts an earth on the relay so there has to be 12v waiting on the other side of the relay coil. The horns are grounded and want 12v from the relay switch to operate, so there are two 12v connection on the relay. Here is a diagram: Doug Edited August 19, 2023 by dougbgt6 Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 19, 2023 Author Report Share Posted August 19, 2023 Thanks guys. Link to comment Share on other sites More sharing options...
GrahamB Posted August 19, 2023 Report Share Posted August 19, 2023 At the risk of complicating things, use a standard relay rated at more than 10 amps. Connect 12V to both 30 and 85, could be a short bridging wire. The horn push is connected to 86 and the horns to 87 1 Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 21, 2023 Author Report Share Posted August 21, 2023 Thanks Graham. Link to comment Share on other sites More sharing options...
DanMi Posted August 21, 2023 Report Share Posted August 21, 2023 Also a likely culprit for horns not working is a missing earth strap across the steering UJ or one missing between the steering rack grease plug and frame. The horn relay is a very simple device and you can easily clean the contacts inside. Link to comment Share on other sites More sharing options...
DanMi Posted August 21, 2023 Report Share Posted August 21, 2023 Also some relays join 30 and 85 internally so only need 1 +ve feed Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 21, 2023 Author Report Share Posted August 21, 2023 Thanks for all the info guys. Got horns working now using 6RA relay with two separate 12v feeds. Another job out of the way. Cheers Brett 1 Link to comment Share on other sites More sharing options...
ean Posted September 16, 2023 Report Share Posted September 16, 2023 Just to continue of the theme of horns not working. I have a Mk2 Vitesse. To state the obvious, it has 2 horns and let me call them horn 1 and horn 2. If I press the horn button with both horns connected I just get a clicking sound . If I disconnect horn 1 and press the button then horn 2 sounds, conversly if I disconnect horn 2 and press the button then horn 1 sounds. ? Any ideas or thoughts, please. Link to comment Share on other sites More sharing options...
Iain T Posted September 16, 2023 Report Share Posted September 16, 2023 12 minutes ago, ean said: Any ideas or thoughts, please. Do you have relays in your horn circuit? Link to comment Share on other sites More sharing options...
ean Posted September 16, 2023 Report Share Posted September 16, 2023 No, not that I can see. Link to comment Share on other sites More sharing options...
johny Posted September 16, 2023 Report Share Posted September 16, 2023 Vitesse doesnt use a relay so this is a classic case of high resistance somewhere in the circuit. Enough current can flow to operate one horn at a time but try both and the volt drop is too much so neither works. First place to look is the earth strap on the steering rack... Link to comment Share on other sites More sharing options...
chrishawley Posted September 16, 2023 Report Share Posted September 16, 2023 2 hours ago, ean said: Any ideas or thoughts, please. I say with complete confidence that I don't know the particular cause of this. But I could suggest a simple method of investigation: Disconnect the 'in' 12v from both horns (purple I think). Then with a suitable bit of flex take a jumper from battery to horn 1 and then on to horn 2. If normality restored then defect is in feed side. If normality not restored then add jumpers from the 'outs' of the horns and touch down to a convenient earth. If both horns now toot togther then defect is in the earth side - not least earth strap as mentioned above. If normality still not obtained then implies defect in horns internally - in particular the contacts. While Lucas 9H horns can be disassembled and fixed it's quite laborious to do so and there are all sorts of replacement options quite cheaply. Link to comment Share on other sites More sharing options...
68vitesse Posted September 17, 2023 Report Share Posted September 17, 2023 Had a similar problem on my Mk1 Vitesse recently, a new wire from the fuse box and I could get them both to sound intermittently. When I went to check the pencil in the steering wheel it fell apart, a new pencil solved the problem but while working on the circuit I added a relay. The new pencil was a very tight fit in the steering wheel and I ended up scrapping it down to fit, another quality part. Regards Paul. Link to comment Share on other sites More sharing options...
johny Posted September 17, 2023 Report Share Posted September 17, 2023 yes strange why some models got a relay and others didnt (penny pinching?). For the current drawn and a sliding electrical connection should have a relay.... Link to comment Share on other sites More sharing options...
ean Posted September 17, 2023 Report Share Posted September 17, 2023 Thanks all. Chrishawley, will give your suggestion a go. The circuit diagram shows wires only for the horn connection, no sign of a relay. A question - why would you use a relay to operate horns when it just needs some cableing? Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 17, 2023 Report Share Posted September 17, 2023 (edited) using a relay implanted in to act as a feed reduces the current through the old contacts to a minimal the main load is passed through the relay only a small current is used to trigger the relay so the this helps all our old switch gear be it horn or lights Pete Edited September 17, 2023 by Pete Lewis Link to comment Share on other sites More sharing options...
Martin OD Posted December 3, 2023 Report Share Posted December 3, 2023 Hi All. Triumph Vitess MK 1. My horn works most of the time but when I turn the steering wheel to a particular place i.e. 1 o'clock it does not work. A little bit left and right of this and it works. It is not the pencil and I am sure it is not the brass ring. My car does not have an earth strap on the bottom of the steering rack over the UJ which makes me wonder how it earths to work most of the time. I think it is earthing out through the steering wheel rubbing on the steering column metal housing, except in one spot. Fitting an earth strap to the bottom of the column looks difficult for lack of space. Any advice/help will be helpful. Link to comment Share on other sites More sharing options...
johny Posted December 3, 2023 Report Share Posted December 3, 2023 its essential and here it is in the manual: Link to comment Share on other sites More sharing options...
johny Posted December 3, 2023 Report Share Posted December 3, 2023 oh and of course there must be this one, item 3 for the coupling, as well: Link to comment Share on other sites More sharing options...
Martin OD Posted December 3, 2023 Report Share Posted December 3, 2023 Thanks. The earth link No 3 is missing and it looks as though it has been missing for a long time but somehow the horn works most of the time. The steering rack one is there. How do you get to the earth link no 3. From below?. it looks impossible from the top. Link to comment Share on other sites More sharing options...
Iain T Posted December 3, 2023 Report Share Posted December 3, 2023 (edited) It's easier with the black side panel removed. It's held on with a couple of nuts around the turret, screws at the front and rad. That's the way I did it as I don't have double uj fingers! Make sure the steering joint bolts are retightened properly as the steering function is pretty important...... Iain Edited December 3, 2023 by Iain T Link to comment Share on other sites More sharing options...
johny Posted December 3, 2023 Report Share Posted December 3, 2023 1 hour ago, Martin OD said: Thanks. The earth link No 3 is missing and it looks as though it has been missing for a long time but somehow the horn works most of the time. As you say it must be working through the steering wheel boss and outer casing which is earthed by one of its mounts to the dash frame. You can prove it by temporarily connecting a good earth to the column impact clamp which should allow the horn to work continually... Link to comment Share on other sites More sharing options...
GrahamB Posted December 3, 2023 Report Share Posted December 3, 2023 I had a similar experience and discovered the earthing strap (3) was missing. Any piece of wire that bridges the insulating disc will work; I think I used a piece of solid copper wire extracted from a piece of mains cable. There was better access than it first appeared making the task relatively easy. Link to comment Share on other sites More sharing options...
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