randybugger Posted November 14, 2019 Share Posted November 14, 2019 Putting in some shiney led warning lamps and can't figure out how to wire the indicator one. Power comes in from either side depending on what way you are turning. Result is it only flashes for one way as the led cant work backwards like a normal bulb.any ideas?cheersTony Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 14, 2019 Member Share Posted November 14, 2019 Which model of Seven?Have you got a single indicator lamp in the dash not in an instrument? That type uses a funny circuit that won't work if you replace the incandescant lamp with a diode, exactly as you've found.But there's a simple way of using an LED which only needs a bit more wiring and a couple of diodes and a new earth. It's described here but IIRC there's something more recent with more detail... 2018, with an explanatory circuit diagram linked from post #9.Jonathan Link to comment Share on other sites More sharing options...
randybugger Posted November 14, 2019 Author Share Posted November 14, 2019 Thanks Jonathon1990 dedion one lightill check that link and see if I can make heads or tails of it.i hoped I could just buy something and plug it in Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 14, 2019 Member Share Posted November 14, 2019 You can!Jonathan Link to comment Share on other sites More sharing options...
Mechanical Moz Posted November 14, 2019 Share Posted November 14, 2019 Do you have a buzzer? If so you may already have the diodes connected to it. I fitted an LED light in the dash but couldn't run the LED and the buzzer off the same diodes so fitted extra ones. However, after a while I found the LED was far more effective at reminding me that an indicator was on than the buzzer so I removed it. So if there is a buzzer present you could remove it and connect the LED up to the old buzzer wiring. Link to comment Share on other sites More sharing options...
randybugger Posted November 14, 2019 Author Share Posted November 14, 2019 No buzzer so I need a diode thingy Y connector. I've tried googling but not sure what I'm searching for Link to comment Share on other sites More sharing options...
randybugger Posted November 14, 2019 Author Share Posted November 14, 2019 Sorry for my ignorance but what would happen if I joined the two wires together and earthed the bulb? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 14, 2019 Member Share Posted November 14, 2019 https://www.google.com/search?q=DIODE+KIT+LED+INDICATORJonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 14, 2019 Member Share Posted November 14, 2019 Sorry for my ignorance but what would happen if I joined the two wires together and earthed the bulb? Whichever side you switch on they'll both illuminate.Jonathan Link to comment Share on other sites More sharing options...
randybugger Posted November 14, 2019 Author Share Posted November 14, 2019 Thanks very much, I’ve learnt a lot, I didn’t even know what a diode was until tonight. Link to comment Share on other sites More sharing options...
randybugger Posted November 22, 2019 Author Share Posted November 22, 2019 Indicators now working.new problem, now ignition light stays on and won’t go out... guess I need some other electric gizmo? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 22, 2019 Member Share Posted November 22, 2019 Have you changed the ignition warming light to an LED?But it’s soluble either way. Jonathan Link to comment Share on other sites More sharing options...
randybugger Posted November 22, 2019 Author Share Posted November 22, 2019 Yes, I've done some reading and it seems I need a resistor in parallel. I tried wiring the original bulb in parallel to see if it would work, the LED now goes out but flickers on and off at tick over. The original bulb doesn't do this. Will a resistor cure this? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 23, 2019 Member Share Posted November 23, 2019 Andrew's notes on the subject.It would be nice to know how many wires are connected to how many terminals on the alternator, but this should work regardless of that.Jonathan Link to comment Share on other sites More sharing options...
randybugger Posted November 28, 2019 Author Share Posted November 28, 2019 Thanks Jonathanread through that post but can't seem to find a resistor the right value anywhere.3 wires on the alternator. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 30, 2019 Member Share Posted November 30, 2019 ... you've got a spec but can't find the product... or you can't find the spec in the archives?Jonathan Link to comment Share on other sites More sharing options...
randybugger Posted November 30, 2019 Author Share Posted November 30, 2019 It says a 40Ω resistor but I can only find much lower numbers? Link to comment Share on other sites More sharing options...
revilla Posted December 2, 2019 Share Posted December 2, 2019 Hi randybugger,If you want to replace the alternator warning light with a regular LED properly you will need to do it as shown below:The 470 ohm resistor limits the current to the LED to around 20 milliamps. Standard red LEDs only require about 2.2 volts across them, connect them directly to a 12 volt supply and they will burn out immediately. You can buy "12V LEDs", these simply contain the 470 ohm resistor or something similar internally. If you get an LED that is designed to work directly on 12 volts then just miss out the 470 ohm resistor. If you get a standard red LED then you will need it. This resistor will be dissipating around 200 milliwatts when the LED is lit so it doesn't need to be anything particularly highly rated. Something like this (470 ohms, 500 milliwatts) will do the job: https://www.mouser.co.uk/ProductDetail/Vishay-BC-Components/SFR25H0004700FR500?qs=sGAEpiMZZMtlubZbdhIBIDRM2xq4Qtv%252B9Fj8WK950Ss%3DThe 40 ohm resistor feeds excitation current to the alternator to get it started reliably. The warning light circuit actually performs a dual function, the lamp lights to indicate that the alternator isn't charging the battery correctly but the alternator relies on the current feed through the bulb to provide the initial excitation of the magnetic field to get it to start reliably. An LED passes a much lower current than an incandescent bulb so without the 40 ohm resistor, the alternator is likely to become unreliable. WARNING: If you leave the ignition switched off without the engine running (so the warning LED on) this resistor will get hot (it will be dissipating 3-4 watts of heat) in the same way as a light bulb gets hot. You need a resistor with a power rating of at least 4 watts. Best idea is a resistor with an aluminium casing which can be screwed to the bulkhead behind the dash to dissipate the heat. I would suggest something like this (40 ohms, 5 watts): https://www.mouser.co.uk/ProductDetail/Vishay-Dale/RE60G40R0C02?qs=sGAEpiMZZMtbXrIkmrvidIpgiW9xqmWBX7%252B6ZL1Tbq4%3DThe 1N4001 diode is sometimes necessary; you may get away without it. It is there to prevent the alternator feeding current back out through the warning 40 ohm resistor when the ignition is turned off. Without this, sometimes people find they can't turn their engines off, they just keep running. There's enough current fed back through the warning system to raise the voltage at the ECU's "ignition sense" terminal above the threshold where it detects whether the ignition is on or off. Note that the diode should be black with a white or silver band around one end. This end is the cathode (NEGATIVE terminal, marked K in the diagram) and must be connected towards the alternator rather than towards the supply. Something like this would do the job: https://www.mouser.co.uk/ProductDetail/Taiwan-Semiconductor/1N4001G-K-R0G?qs=sGAEpiMZZMve4%2FbfQkoj%252BOpeCiqr8ESJlhwZD%2FsxJwA%3DAll of the above parts are from the same supplier (Mouser Electronics) and available to order in multiples on 1.Hope that helps,Andrew Link to comment Share on other sites More sharing options...
randybugger Posted December 2, 2019 Author Share Posted December 2, 2019 Thanks Andrew, brilliant, Tony Link to comment Share on other sites More sharing options...
randybugger Posted December 2, 2019 Author Share Posted December 2, 2019 Thanks Andrew, brilliant, Tony Link to comment Share on other sites More sharing options...
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