Led indicators

S0updragon

Well-Known Member
Well I decided to change all my bulbs for led (except headlamps). Indicators used to work fine. Replacing both flasher relays for led to get them to flash properly. However now when indicating the other direction also flashes dimly and the green dashboard lamp doesn’t do anything. I disconnected lhs wire to d/board lamp and that sorted out the wrong lighting side and went on holiday. Going back to fault finding now I have discovered that connecting all wires and taking green bulb out makes indicators work properly. Green bulb hasn’t blown. Is it because the bulbs are led and the hazards are interlinked so there is voltage leaking in making wrong leds blink as well due to far less wattage compared to filament bulbs? I’m going to see if I have a little d/board led bulb to see if that lights up.
 

S0updragon

Well-Known Member
Blooming earth faults lol. As the dashboard lamp only has 2 wires and they are lhs and rhs and in a plastic dashboard how is the earth/negative formed. My little led bulb I found is polarity specific so assume won’t work as +ve in will switch
 

S0updragon

Well-Known Member
I can only think that with new bulbs being such low wattage they are being affected by weak earth fault as the indicators worked fine before bulb and relays swap
 

S0updragon

Well-Known Member
Well the front indicators are new having taken one off it has a metal tag that bends down to contact bodywork which it would if it was like a ceiling downlight but it’s not so how it gets a proper earth is beyond me so connected a wire to it and fed it into cab. Taking of fabric shroud could actually get my fingers in to bend it down but it doesn’t really bend that far with decent contact. Then decided I haven’t really got a nice -ve point for all this messing about so decided to get a good fixing and bring it into the fuze box area to make this and future things easier. With wires all over the place I have stopped for the day as it’s always fun going back to something and trying to remember what on earth you were doing. Every time there’s a problem it cements my view that half the time it’s all black magic and witchcraft that makes it work. I’m sure all of you with the knowledge will laugh but don’t forget it’s us stupid people that make you really stand out :) :)
 

Panky

Administrator
Staff member
The front fitting usually earth though one of the three fixing screws that hold the fitting to the body. I seem to remember there is a metal tab from the bulb holder that forms one of the fixing holes.
 

S0updragon

Well-Known Member
Ah I’ll check when I do the other one. I didn’t notice a tag or wire etc but I will double check in case I’m pointlessly earthing the wrong bit lol. Thank you
 

Martin Selwood

New Member
How are you getting on, SD? Did you sort it? I'm re-wiring our Tilly during her re-build and going to LED her, and funnily enough one of my biggest obstacles is the simple Flasher set up the Commer's use.
When you indicate left or right it puts power to the relay, which in turn sets power to the lamp on the dash. So, if you start playing with the wiring, when you send power to one indicator, it passes through the dash lamp and to the other indicator.
Be interested to know if you found a simple work around, which keeps the dash lamp working?
 

S0updragon

Well-Known Member
Hi. Haven’t managed to continue with it. If re earthing front indicators doesn’t do the trick I was thinking of splicing it into wire coming out of relay as parallel circuit or +ve in and other to earth. Only other option would be 2 arrow lamps on dash.
 

S0updragon

Well-Known Member
Have I lost all contact with reality? Surely the bulb should light when indicating. Dashboard bulb. It flashes continuously when one wire goes to ground so bulb works ok. I’ve tried with a dashboard led in case the amps are really low with no joy. image.jpg
 

Panky

Administrator
Staff member
I'm no sparky but it it correct to wire the bulb in parallel? I would have thought the current would take the path of least resistance.
 

S0updragon

Well-Known Member
Ah. I would have thought there would be enough current to light a tiny led. Maybe not. Tried google but no help. I need a physics teacher lol
 

jimberlake

Well-Known Member
I’m not great on these things but is the flasher unit grounded? Electronic ones (I think the standard flasher units don’t work with leds) may need to be grounded whereas old ones don’t. I might be talking rubbish here though :)
 

S0updragon

Well-Known Member
I’ve got the led flasher relays. Only difference is they work on lower current. Filament relays flash too quickly or solid on. Motorcycle led indicators used to come with a resistance ballast to splice in to sort out flashing. You had to be careful where you put them as they got very hot. It’s the blooming dashboard lamp that’s the issue lol as that’s wired weirdly.
 

colinthefox

Well-Known Member
Here's a quote from the Halfrauds website................

"LED bulbs are highly efficient and last a long time, but you'll only be able to benefit from them if your car's manufacturer has installed them - it's currently illegal to add LED bulbs to your car as an aftermarket installation."
 

S0updragon

Well-Known Member
Whoops. I’m not too worried about indicators and side lights as they aren’t brighter than filaments. I do know if you put leds into headlights it cocks up the beam pattern and is potentially dangerous for oncoming traffic with glare etc.
 
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