Confusing bulbs

[The End]

Just to clear it up now, I am a n00b when it comes to electrical components.

A few months back, the bulb behind my speedo which illuminates it failed and I had to replace it. It was one of these (halogen?)

277743


I tried many electrical and lighting stores and could not find a replacement bulb. Jaycar recommended I go for a LED version of the bulb, same fitting but LED. It illuminates the speedo with a brighter light and looks better (irrelevant though...) however it is only brighter when I have the revvs on the bike over 3k (idles at ~1500). At idle, it is pretty dim. I'm thinking it draws too much current to what the battery/electrical system is putting out at idle?

The LED one looks like this:

277744


The bulb that illuminates the rev counter has just stopped working, so it needs to be replaced. Am I better to go with a halogen(?) one or LED?

My parts manual says the stock halogen(?) one is "4ST–H3517–10 .BULB (1.4V-3.4W T10)". Which to me suggests it is 1.4 volts, 3.4 Watts with a T10 fitting?

The LED bulb I got from Jaycar draws 12volts - unsure of wattage.

Advice?

[Gareth123]

I bought myself a small box of these slot in bulbs a few years back from BNT. You can definitely still get them. If I recall correctly I had to buy the whole box of 10 since they have very little call for these. I think they were only $1 each though.

So yeah, I'd go and hit them up or another auto store. Just take one of the old bulbs in with you.

Edit - Sorry, went and had a look at the box, the bulbs I have are 12v - 1.5w

Which means they would probably be useless for your bike. I still think BNT or Repco should be able to get them in for you though.

[gammaguy]

The led is the way to go,I converted all my bikes ages ago

Trade me have plenty of them

[The End]

Cheers for the replies. My only concern about fitting another 12v LED bulb is that its going to draw too much current for what the whole electrical system can put out. At idle, the whole lighting system is pretty dim - headlight included - and ideally I'd rather not draw yet again more power than what it is providing?

[MSTRS]

Is your bike a 6 volt or 12 volt system? Not many, if any, are 6 volt these days.
And why/how would a 1.4v bulb not burn out in a higher voltage system?

[The End]

Is your bike a 6 volt or 12 volt system? Not many, if any, are 6 volt these days.
And why/how would a 1.4v bulb not burn out in a higher voltage system?

My manual says

"Electrical:

Charging system - 14 V, 100 W @ 5000 r/min
Battery - Voltage, capacity - 12v, 7 AH

Meter Lighting 12 V, 3.4 W x2"

[DrunkenMistake]

Cheers for the replies. My only concern about fitting another 12v LED bulb is that its going to draw too much current for what the whole electrical system can put out. At idle, the whole lighting system is pretty dim - headlight included - and ideally I'd rather not draw yet again more power than what it is providing?


The LED bulb should draw LESS current from the system and you will find they are alot brighter too

EDIT:
Actually I think I may have read that wrong, Are you worried about the bulb getting shagged from the bike or the electrical system getting shagged by the bulb?

[jellywrestler]

Just to clear it up now, I am a n00b when it comes to electrical components.

A few months back, the bulb behind my speedo which illuminates it failed and I had to replace it. It was one of these (halogen?)

277743


I tried many electrical and lighting stores and could not find a replacement bulb. Jaycar recommended I go for a LED version of the bulb, same fitting but LED. It illuminates the speedo with a brighter light and looks better (irrelevant though...) however it is only brighter when I have the revvs on the bike over 3k (idles at ~1500). At idle, it is pretty dim. I'm thinking it draws too much current to what the battery/electrical system is putting out at idle?

The LED one looks like this:

277744

d


The bulb that illuminates the rev counter has just stopped working, so it needs to be replaced. Am I better to go with a halogen(?) one or LED?

My parts manual says the stock halogen(?) one is "4ST–H3517–10 .BULB (1.4V-3.4W T10)". Which to me suggests it is 1.4 volts, 3.4 Watts with a T10 fitting?

The LED bulb I got from Jaycar draws 12volts - unsure of wattage.

Advice?

dunno what makes you think it's a halogen looks like a normal incandescent to me.
replace it with whatever you want, the wiring will handle both with ease.

[Woodman]

Yep thats a pretty common incandesant dash bulb. Not hard to find at all. I hate bright dash bulbs.

[The End]

The LED bulb should draw LESS current from the system and you will find they are alot brighter too

EDIT:
Actually I think I may have read that wrong, Are you worried about the bulb getting shagged from the bike or the electrical system getting shagged by the bulb?


I am more concerned about the bulb not getting enough current (not sure if this is the technical term) so that it doesn't glow bright enough. As I said earlier, the current LED bulb I have under the speedo gauge is very dim until I get the revs up on my bike.

[steve_t]

Isn't that just a normal T10 (W5W) wedge bulb? They're used for parking lights and number plate lights and are very common. Repco or Supercheap will have them. Actually, any automotive place should have them. LEDs do draw little current relative to incandescent lamps. Often if you want to use an LED, you need to wire in a resistor of some sort as well. Probably easier just to return to incandescent

[The End]

Isn't that just a normal T10 (W5W) wedge bulb? They're used for parking lights and number plate lights and are very common. Repco or Supercheap will have them. Actually, any automotive place should have them. LEDs do draw little current relative to incandescent lamps. Often if you want to use an LED, you need to wire in a resistor of some sort as well. Probably easier just to return to incandescent

Is it still worthwhile going for a second LED bulb then? I mean if it draws less current and last longer then surely it is the better option? Is wiring in a resistor particularly hard work?

[steve_t]

Is it still worthwhile going for a second LED bulb then? I mean if it draws less current and last longer then surely it is the better option? Is wiring in a resistor particularly hard work?

Not sure. You'd have to work out how many ohms you'd need to add. With LED indicators you can just change the flasher unit but with a dash light, not sure. Maybe Bogan or another physics person or an electronics/electrician can help

[Coldrider]

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.

[Henk]

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.

[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.

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[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