Confusing bulbs

[bogan]

Go for the LED one. It almost certainly has the resistor built in to the holder, or it would have popped almost instantly.

LEDs have a voltage drop of app 0.2volt each junction, so need a resistor to drop the other 11.8 volts. In the four led example above 11.2 volts need to be dropped (in the perfect world 60 LEDS in series would not need a resistor 0.2 X60 =12v).
When your bike is below 3000rpm your voltage output may be a bit low, your incandesant lamp was probably dim but overrated so you wouldn't notice the difference.

Its often color dependant, but white ones are generally around 2-2.4V iirc. I have no idea where you get 0.2V from, you have to pay extra to get any sort of diode with a voltage drop that low. Often manufacturers just put 4-6 in series, so they don't need a resistor, or maybe a very small one depending on what the final values works out to be.

Resistors are usually add when people switch to LED for indicators, they don't draw enlightened current to make the flasher relay work in old bikes so the indicators either don't flash at all or do it. Insanely fast. Sounds like your charging system isn't putting out what it should at low revs, where an incandescent rated at 12v will glow more dimly at lower voltages an LED array will need a minimum voltage to work at all. I'd still go for the LED in this case though, should last forever where the incandescent a will keep blowing on occasion.

That'd be my guess too, fix the problem rather than fixing the symptom.

[Fergus]

You definitely don't need a (current limiting/series) resistor, that will make the problem worse...

The supply voltage is to low for your LED, either the LED is the wrong spec for your supply voltage or your supply voltage (ie battery) is under spec...

[Erelyes]

Pics of the bulbs in my own Scorpio.

speedo is a stock 3.4w T10 wedge.
rev counter is a white quad-LED from jaycar (http://jaycar.co.nz/productView.asp?ID=ZD0394)

neutral indicator is a white single-LED from jaycar. (http://jaycar.co.nz/productView.asp?ID=ZD0390)
hi-beam indicator is a stock 3.4w T10 wedge.

I tried the single-LED in the rev counter but it didn't cut the mustard. I wonder if this is what the OP 'The End' had in there.

No idea what wattages either of the jaycar items are. Probably no more than .2-.3w for the single and .6w for the quad.
Edit; ZD0390 = 15mA at 12 volts (.18w)
ZD0394 = 25mA at 12 volts (.3w)

The parklight bulb in the headlamp is currently a 3.4w wedge as well. Wonder what one of the 1 watt heatsinked LED jobbies on trademe would be like in there!

Needless to say I'm gonna get another one of each and do the speedo/hibeam too. Although I'll go for a ride first and make sure the neutral isn't TOO bright!

Putting either of the LED bulbs in the indicator.... indicators? made it flash slightly slower... not a big amount tho.

PS as you can see this is pretty much at idle (choke was on). Give it a rev and they're all a touch brighter.

[Coldrider]

Good to see you have it sorted. The green stripey thing on the right leg is the inbuilt resistor that the others reckon should not be there.

[The End]

I tried the single-LED in the rev counter but it didn't cut the mustard. I wonder if this is what the OP 'The End' had in there.

I ended up replacing both the rev and speedo stock bulbs with the Jaycar quad LED ones. It illuminates well although I find it slightly dimmer towards the bottom of the gauge as LEDs don't spread the light as far as a stock bulb.

I haven't touched the high beam or neutral bulb as they are both still working fine.

The next thing on my to do list is to get a better headlight bulb. It's shockingly dim at night...

[Erelyes]

Yeah I think there are challenges there.

http://jaycar.co.nz/productView.asp?ID=SL3368 looks tempting but I think is technically illegal. Beam pattern might be pants too (which is what would cause the most attention from the law, if one was to choose to use it).

Only other option is putting a 55/60w bulb in there (or 7" headlight from another model of bike) and upgrading the wiring/generator etc to suit.

[Coldrider]

Using a HID lamp unit in a 'non HID reflector' unit is what is illegal.

[bogan]

Using a HID lamp unit in a 'non HID reflector' unit is what is illegal.

...even if they do not require even one cut to the wiring!

And where's the fun in that anyway, just doing some wiring for my own HID setup (correct reflector and lens) this weekend as it happens.

[Erelyes]

...even if they do not require even one cut to the wiring!

And where's the fun in that anyway, just doing some wiring for my own HID setup (correct reflector and lens) this weekend as it happens.

Mmm, be interested to see the results