LED rear light wiring problem

[mightlife]

I’m trying to get a homemade tail tidy together for my Husqvarna SM, but am having problems connecting the LED rear light I bought for it.

I’ll be the first to admit that I’m a bit of a dunce when it comes to most of this kind of stuff, especially electrics :unsure:
So forgive me if my explanation isn’t that great, but I’d appreciate any help you could give.

I did the following:
removed the stock rear assembly and unplugged the rear light and indicators.

tested the new LED rear light on a variable voltage power adapter (that I use to power a small guitar effects unit) - everything was okay i.e. two different levels of brightness when switching (what I believe to be) two live wires, one for the running light, the other for braking.

There are three wires from the stock rear light to the connector, I took note of their colours and what I assume their function is:
Green - earth
Yellow - live for running light
Blue - live for brake light
This is how it is on my LED light.

replaced the ‘plastic connectors’ that joined the rear light to the loom (and vice versa) with new ones, ‘male’ on the loom and and ‘female’ on the stock rear light and LED light making sure that I wired the plastic connectors so that the coloured wires were in the same place on both the ‘male’ and ‘female’ connectors.

it was time to test the connections - the stock light works okay with the new connectors, although there is not much difference between the running and break light brightnesses.
But the LED light did not light up at all

Strangely (to me), when I attach the blue wire from the LED to the green one from the loom and then the yellow wire where it should be (LED to loom) there is light from the LEDs.

Note.
There is enough power in the battery.
The LED light DOES work (both running and brake).
I assume that the green loom wire is earthed correctly as the stock rear light works okay. This could be the culprit, but I don’t know how to go about fixing the situation.
I don’t have money to buy a multimeter BTW

I thought this would be a simple swap over of parts like it, basically, is with LED indicators, but not yet
Any suggestions or requests for me to carry out further tests would be welcome.
Thanks.
G

Here are some photos.
(the stock rear assembly)
(what I’m aiming for)
(the new ‘plastic connectors’ on the LED light and loom wires)

Attachments

[mightlife]

anyone got any ideas on this one? it’s still bugging me.

[shiver]

When I wired up my led tail light it was a free for all as to which what went where. Just give it a go on various wires

[NumNum]

By the look of the pics you have one of the real cheap ones. Little oval shaped thing with four whites for a plate light and 8 or so for brake and running .hard plastic backging plate . . ? The reason there is little difference in brake and running is due to general crapness. No matter how you wire em up it wont fix that . I just removed one from my yamaha as it broke after 3 days due to vibration and upgraded to a rubber sealed one that works much better . But cost twice as much .

[mightlife]

Thanks for replying.

But, I’ve tried that with no luck I’m afraid.
Tried it off the battery last night and it works, so I’m sure the paower is there.

And it doesn’t look like a fault with the wiring because the stock light works as it should. I think that it might be something specific to LEDs rather than filament bulbs as far as their current is concerned.
I read somewhere that LEDs required a particular type of current, but I’m clueless when it comes to the specifics, so I don’t know what to do.

shiver (26/10/2011)

When I wired up my led tail light it was a free for all as to which what went where. Just give it a go on various wires

[NumNum]

The light you have bought has the circuit within it that corrects the voltage to be led compatible . Idealy I would like to try your light next to another one the same as with those cheap leds nothing is guaranteed even when new .

[szymon]

What voltage do you have coming out of the new connectors? Put in a blank female connector and measure on the wire with a multimeter (in both states, normal and braking) and compare vs the minimum voltage for the LEDs. The fact that there is not much difference between the running and break light brightness with the original lights on the new connectors make me think you’re suffering a voltage drop with the new connectors. If you don’t have actual specs for the led’s, then check what the minimum voltage you need to drive them is. If the voltage you’re getting is low, I’d change from the “new” connectors (which frankly look like cheap rubbish) to something like andersen powerpoles.

-simon

[mightlife]

Sorry if I gave the wrong impression, but there is actually a very noticable difference between the running and brakes states of the LED light (it’s almost bright enough to blind).

It does have a hard plastic backing plate and four white LEDs for the plate light, but there look to be about 16 reds.

It came in a black metal housing which I didn’t need, (so am not using); for safety’s sake, I plan to put some sealant in the right places when I’m ready to install it.

NumNum (26/10/2011)

By the look of the pics you have one of the real cheap ones. Little oval shaped thing with four whites for a plate light and 8 or so for brake and running .hard plastic backging plate . . ? The reason there is little difference in brake and running is due to general crapness. No matter how you wire em up it wont fix that . I just removed one from my yamaha as it broke after 3 days due to vibration and upgraded to a rubber sealed one that works much better . But cost twice as much .

[NumNum]

If you are really stuck I am in west london if you want to bring it down to my workshop at the weekend I have multi meters ,connectors various stand alone voltage supplies everything that could be needed . . Even a full time bike mechanic and an electrician .

[mightlife]

That’s an interesting idea about the connectors. They are certainly not as substantial as the stock ones. It was difficult enough sourcing them as it is, but I’ll look out for some better alternatives.
Thanks.

Could the possible drop in voltage be the reason the LED light is not playing ball?

BTW - no multimeter I’m afraid

szymon (26/10/2011)

What voltage do you have coming out of the new connectors? Put in a blank female connector and measure on the wire with a multimeter (in both states, normal and braking) and compare vs the minimum voltage for the LEDs. The fact that there is not much difference between the running and break light brightness with the original lights on the new connectors make me think you’re suffering a voltage drop with the new connectors. If you don’t have actual specs for the led’s, then check what the minimum voltage you need to drive them is. If the voltage you’re getting is low, I’d change from the “new” connectors (which frankly look like cheap rubbish) to something like andersen powerpoles.

-simon

Thanks for the offer Num, unfortunately, I’m in Barcelona (have been for about a year now).

Come over and check out the roads around here!

NumNum (26/10/2011)

If you are really stuck I am in west london if you want to bring it down to my workshop at the weekend I have multi meters ,connectors various stand alone voltage supplies everything that could be needed . . Even a full time bike mechanic and an electrician .

[mightlife]

That’s an interesting idea about the connectors. They are certainly not as substantial as the stock ones. It was difficult enough sourcing them as it is, but I’ll look out for some better alternatives.
Thanks.

Could the possible drop in voltage be the reason the LED light is not playing ball?

BTW - no multimeter I’m afraid

szymon (26/10/2011)

What voltage do you have coming out of the new connectors? Put in a blank female connector and measure on the wire with a multimeter (in both states, normal and braking) and compare vs the minimum voltage for the LEDs. The fact that there is not much difference between the running and break light brightness with the original lights on the new connectors make me think you’re suffering a voltage drop with the new connectors. If you don’t have actual specs for the led’s, then check what the minimum voltage you need to drive them is. If the voltage you’re getting is low, I’d change from the “new” connectors (which frankly look like cheap rubbish) to something like andersen powerpoles.

-simon

Thanks for the offer Num, unfortunately, I’m in Barcelona (have been for about a year now).

Come over and check out the roads around here!

NumNum (26/10/2011)

If you are really stuck I am in west london if you want to bring it down to my workshop at the weekend I have multi meters ,connectors various stand alone voltage supplies everything that could be needed . . Even a full time bike mechanic and an electrician .

[NumNum]

I find the roads in the club med country’s are best attacked in a hire car

[biker_dan]

did u sort this? on some lights yellow is used as earth…was on the same sorta lamps i got from aye gee’s…

[mightlife]

biker_dan (01/12/2011)

did u sort this? on some lights yellow is used as earth…was on the same sorta lamps i got from aye gee’s…

Sorry mate, yes.

I’ve got it working exactly how I wanted.

Check the vid below for the finished tidiness!

I made the stupid mistake of putting the same coloured wires together, in fact they were connected differently.
I worked this out by taking a closer look at how the original was wired up and then trying all the combinations again.

It helped for the engine to be on as well, the brake light sometimes doesn’t come on without the engine turning over. Perhaps this has to do with the fact that I’m on a single.

All good now though, thanks,
G

Husqvarna SM610 with some 'mods'

[shiver]

Result I had to find out the hard way with the clear alternatives sv light I had its just trial and error