MilesA Posted October 18, 2022 Report Share Posted October 18, 2022 My 6 came replete with period Fiamm two tone air horns. These are operated through an original 3 pin Fiamm relay* and a separate switch below the dash. Good, strong sound. The original horns are in place. They are not wired through the original horn relay which is unused (picture below). They operate via the horn push but sound pathetic (one not working/poor power supply/ poor earth?). I haven't quite traced all the wiring for them yet. I am tempted to keep the Fiamms as I like the safety element of being heard when I need to be! But, the separates switch delays use / is distracting and is in the way of my knee when driving (easily moved though) So.... 1. Are the Fiamms legal? I think so. They don't play a tune and never been mentioned on any MoT reports. 2. Any reason why I can't wire the Fiamms into the horn cabling so they are operated by the horn push? 3. Can all 4 horns be wired into the horn push (utilising the original relay for the original horns or piggy backing on the Fiamm relay)? Redundancy or overkill??? * Not being too well versed in electrickery I was confused by the original 3 pin relay but suspect the yellow fixed wire means it is in truth a 4 pin relay. Pictures below Many thanks for your thoughts as ever. Miles Quote Link to post Share on other sites
RobH Posted October 18, 2022 Report Share Posted October 18, 2022 (edited) This is the original wiring scheme, the yellow wire makes it into a 4 connection relay as you say as it links supply on pin B to the top of the relay coil. You can piggy-back it into the original circuit by connecting S on this relay to W2 on the existing horn relay (purple/black wire) so all horns sound together. Air horns are legal provided the tone is constant and not warbling or playing a tune. (The regs for post-1973 cars says they must not be 'strident' but this does not apply to earlier classics. ) Edit - if you are not using the original horn relay the horn push will be attempting to pass a rather large current which is probably why the horns sound anemic. Not good for the horn push either. Edited October 18, 2022 by RobH Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 18, 2022 Report Share Posted October 18, 2022 Do not forget to oil the compressor. Red cap on top of it, flick it off and drip in oil. Replace cap to keep crud out. Quote Link to post Share on other sites
Charlie D Posted October 18, 2022 Report Share Posted October 18, 2022 Miles, I once had an old Maserati (I’m not wealthy. It only cost $500). It had both an air horn and an electric horn. They operated from two different switches. One Marked “Town horn” the other marked “Country horn”. You could do the same and turn your horns into a conversation piece. 1 hour ago, RobH said: The regs for post-1973 cars says they must not be 'strident' I wonder if MOT stations have a 'strident meter” to test them. You could have a good debate with a police officer about the definition of 'strident' if ever you were stopped. (I think I know who would win.) Charlie Quote Link to post Share on other sites
MilesA Posted October 18, 2022 Author Report Share Posted October 18, 2022 Rob Thanks as ever. Need to rewire the original TR6 horn relay (think I know where the original cables have been secured) and will piggy back as you suggest. I am pretty sure your 'Edit' explanation is what is going on. Peter Thanks spotted that. A couple of drops of 3 in 1 annually seems to be the consensus. Charlie Attracted by the 'Town' and 'Country' idea but perhaps 'Italy' and 'UK' might be an option! Miles Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 18, 2022 Report Share Posted October 18, 2022 (edited) 26 minutes ago, MilesA said: Rob Thanks as ever. Need to rewire the original TR6 horn relay (think I know where the original cables have been secured) and will piggy back as you suggest. I am pretty sure your 'Edit' explanation is what is going on. Peter Thanks spotted that. A couple of drops of 3 in 1 annually seems to be the consensus. Charlie Attracted by the 'Town' and 'Country' idea but perhaps 'Italy' and 'UK' might be an option! Miles I had Citroen that had the same approach with their light switches. Off, Ville. Rue. You got Off at the first position, then side lamps and dip on the second position then dip and high beam on the third. both lamps on conditions were controlled by operating the ‘dip’ switch stalk, depending on the lamp switch position selected. PS Facel Vega HK500 had the selectable horn switch like the Maserati. Edited October 18, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
TR Paul Posted October 22, 2022 Report Share Posted October 22, 2022 Aston Martin also employed a 'town & country' horn switch. I've got some (non-period) Fiamm air horns on my '6, which replace the factory items, wired through the original relay. If Mr M.o.T man doesn't object to the level of 'stridentness', I can't see (or hear...?) the problem; horns are a safety feature, so there's no point in having quiet ones! (my old modified Austin A30s' air horns saved it from being squashed by a reversing Chelsea tractor in a a wet & dark car park, a few years back) Cheers, Paul. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 28, 2022 Report Share Posted October 28, 2022 Strident? Quote Link to post Share on other sites
RobH Posted October 28, 2022 Report Share Posted October 28, 2022 (edited) Klaxon. I've got one of those on my 1930 M type. Edited October 28, 2022 by RobH Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 28, 2022 Report Share Posted October 28, 2022 3 hours ago, RobH said: Klaxon. I've got one of those on my 1930 M type. If you have a spare I know a man with a ‘30’s MG seeking one Peter W Quote Link to post Share on other sites
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