MARK Posted March 9, 2023 Report Share Posted March 9, 2023 I have had an indicator buzzer fitter for quite a few years to my 73 TR6. This was wired across parallel to the flasher unit. Recently I have had problems with the indicators and the buzzer. I have changed the switch to a tested good one. Changed the flasher unit and rewired it. Earthed all the rear lights with additional earthing points and all seemed ok. However I found applying the brake affected the buzzer making it sound weak, a bit like a strangled cat!! I found removing high power LED stop /tail and fitting normal filament bulbs stopped the problem. A long Club run on Sunday was completed with no issues. When re fitting the LED stop / tail bulbs the problem returns with the buzzer but indicators still work ok at normal speed. Switching on headlights does have any effect to the buzzer. I find it hard to believe that the LED bulbs could cause a large voltage drop but I don't know what to investigate next other than trying another set of LED bulbs. MARK Quote Link to post Share on other sites
Kevo_6 Posted March 9, 2023 Report Share Posted March 9, 2023 Hi Mark, I think it’s more likely that it’s a flasher relay unit. Not all electronic flasher relays work with LED lamps. I had a similar problem when changing over to LEDs and after talking to Classic Car LEDs (where I bought the lamps) I change my old electronic flasher relay with one of theirs and no problem since. https://www.classiccarleds.co.uk/products/12v-electronic-indicator-flasher-relay-classic-car-with-oe-click-x-l-p-2-3-pin?_pos=3&_psq=flasher+relay&_ss=e&_v=1.0 Quote Link to post Share on other sites
RobH Posted March 9, 2023 Report Share Posted March 9, 2023 The fact that the brake-lights affect the indicator circuit makes me think this is still something going on at the rear light cluster. The two circuits are entirely separate except where the lamp cluster is earthed and there should be no interaction at all. The clearing of the fault when normal stop bulbs were used is also a pointer. Are the indicator lamps LEDs also ? Quote Link to post Share on other sites
Kevo_6 Posted March 9, 2023 Report Share Posted March 9, 2023 I should have read the OP thoroughly, Rob your right there is no mention of LED indicator bulbs. Quote Link to post Share on other sites
MARK Posted March 9, 2023 Author Report Share Posted March 9, 2023 The indicators are all normal filament bulbs. The flasher unit is a new original type. The LED stop / tail bulbs are very bright and when testing with a battery charger have a noticeable buzz when stop terminal is connected. I am going to try a direct feed from battery to stop lamps to eliminate brake light switch/circuit problems. Any suggestion welcome as I'm finding this problem time consuming and frustrating!!! MARK Quote Link to post Share on other sites
RobH Posted March 9, 2023 Report Share Posted March 9, 2023 Being wired across the flasher unit, the buzzer only gets power when the flasher relay switches off, so it takes power from the flasher and earths through the indicator lamps. The power feed to the flasher unit comes from a common point on the instrument voltage stabiliser which also powers the brakelight circuit. The buzz you hear from the LED brake bulb is probably due to the way the bulb works. Many of them incorporate a chip which controls the brightness by switching the LED on and off rapidly. It is possible that switching noise is being fed back via the power feed and is interfering in some way with the power to the buzzer. If you have a capacitor of around 10 microfarads at 15 volts or more, you could try connecting that with + to the B terminal on the flasher unit and - to earth. That should attenuate the interference. Quote Link to post Share on other sites
FatJon Posted March 10, 2023 Report Share Posted March 10, 2023 If the earths on the rear lights are not good you will get a back feed through the indicator bulb filaments to the buzzer. That will possibly make it squawk when the brakes are on and weaken the ground when the indicators are on and make the buzzer fainter. Quote Link to post Share on other sites
MARK Posted March 10, 2023 Author Report Share Posted March 10, 2023 Thanks RobH ! Would changing the flasher unit to a LED compatible unit sort it ? Or do you think I should try and source some better quality LED stop/tail lamp bulbs? MARK Quote Link to post Share on other sites
RobH Posted March 10, 2023 Report Share Posted March 10, 2023 I don't think changing the flasher unit will make any difference. You only need that to suit LED flasher bulbs, because the bulbs don't draw enough current to make the standard one work. As I understand it that is not your problem here. Different LED stop bulbs might sort it, since the standard bulbs seem to, but if they don't ........... The thing is from your description it had been working OK for some time and this problem has started recently. That either means something has failed or it is due so some change you have made. As we have said the most likely cause of a fault is corrosion in the light-cluster earths but you apparently have changed those with no effect and the fact that normal bulbs work OK confirms that. However, if this problem coincided with the installation of the LED stop bulbs, then clearly those are to blame. Quote Link to post Share on other sites
MARK Posted March 10, 2023 Author Report Share Posted March 10, 2023 Thanks RobH. I have ordered two bulbs from Better Car Lighting. Not cheap but if it sorts my problem worth it !!!! . Talking to the guy there, cheap LED bulbs can cause problems. So fingers crossed !! MARK Quote Link to post Share on other sites
MARK Posted March 15, 2023 Author Report Share Posted March 15, 2023 New bulbs arrived ! Fitted and all is now well !!!!!! Indicator Buzzer working normally and bright rear back and brake lights !!! So there you are, cheap LED brake lights can cause you problems! The bulbs were tested many times off the car with no problem and a considerable amount of time was spent checking earths and adding more ! . Maybe RobH can explain and much thanks to him for his words of wisdom ! MARK Quote Link to post Share on other sites
matttnz Posted March 16, 2023 Report Share Posted March 16, 2023 Late to the party here but am I right to assume your buzzer circuit is so you can hear the indicator? The original flasher unit is pretty stealthy. I fitted a modern (no LEDs here) flasher unit and the "click" is clearly audible, even from the passenger foot well install. Might be worth getting one of those too, they're not exppensive? Quote Link to post Share on other sites
CK's TR6 Posted March 17, 2023 Report Share Posted March 17, 2023 motorcycle flasher unit that beeps. works like a charm. Quote Link to post Share on other sites
Mike C Posted March 17, 2023 Report Share Posted March 17, 2023 7 hours ago, CK's TR6 said: motorcycle flasher unit that beeps. works like a charm. That's what I use. I had to cover mine with duct tape , as driving around town with the top down it sounded like a forklift. Quote Link to post Share on other sites
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