Hey guys,

I found a few other threads related to getting more light from our bikes, but no one really effectively answered this question:

Is it okay to use a higher wattage bulb in our headlights?

1. Will it draw too much current

2. Can the wiring in the bucket handle the additional heat

3. Any recommendations on bulbs? PIAA, Sylvania,etc.

Tired of riding in the dark,
Luke

Oh,

I should also mention I'm swapping the stock eyebrow and bucket for a side-mount 7"er

Cheers

The H4 connectors are pretty easy to melt in a sporty. I think it usually happens from vibration, causing small arcing, causing corrosion, causing heat, causing melted plastic. That whole cycle would probably happen faster with higher wattage bulbs.

Have you checked out the "blue" type of bulbs? They throw out a lot more light in the same wattage package.

Gazza

Hey guys,

I found a few other threads related to getting more light from our bikes, but no one really effectively answered this question:

Is it okay to use a higher wattage bulb in our headlights?

1. Will it draw too much current

2. Can the wiring in the bucket handle the additional heat

3. Any recommendations on bulbs? PIAA, Sylvania,etc.

Tired of riding in the dark,
Luke


Hi Luke.
Ok, I'll giv'er a go.....
1) No.
2) No.
3) Sylvania Silver Stars.

And the next time you find yourself riding in the dark......wait fort it.....

Use the Force, Luke!:roflblack :doh :hidechai :sofa

I forgot those bulbs are the same 55/60w (whatever). Is there really a such thing as a "motorcycle specific" bulb? I read a few other posts making this claim but am not sure what to think of it. They are supposedly designed to withstand the increased vibration?

Anyway, anyone have good luck with a certain brand. I'd like to get it right the first time if I'm going to drop $25+ on a bulb.

Luke

Hi Luke.
Ok, I'll giv'er a go.....
1) No.
2) No.
3) Sylvania Silver Stars.

And the next time you find yourself riding in the dark......wait fort it.....

Use the Force, Luke!:roflblack :doh :hidechai :sofa

So to #2, the wiring CAN'T handle the heat? Oh, and I've never heard that before...ever.

The insulation on the wire doesn't have a problem, it's the cheap black plastic that holds the terminals together. I've replaced mine once, I think Bert did his twice and I've heard a lot of other folks report the same problem.

I don't think the bulb heat itself causes the melting connector housing. It seems like it's usually a result of increased heat from a corroded terminal, but I'd bet that having more heat on the terminals to begin with would make them corrode a whole lot faster.

http://www.xlforum.net/vbportal/forums/showthread.php?t=3512

Gazza

So to #2, the wiring CAN'T handle the heat? Oh, and I've never heard that before...ever.

That is correct, the higher watt bubs run at a a bit higher temp, and the extra amps being pulled through the wiring raises the temperature, and yes it will melt.
I have seen this with bikes and cars....fix them quite a few time at work.

Thanks for the link. That's what I needed to know:clap

Jeffy does have a point.. enough current will melt the insulation. Above I said it wouldn't matter, but I don't know what wattage bulbs the 18 guage wire on our headlights will support before they start to melt. I'd trust Jeffy's advice he's a pretty darned experienced auto mechanic.

Gazza

Like Jeffy said...........Sylvania Silver Stars do a nice job.

Like Jeffy said...........Sylvania Silver Stars do a nice job.

The biggest problem with Silverstars is their longevity. Sylvania rates them about 1/5 the life of normal bulbs

I replaced my stock headlight bulb with a Osram-Sylvania ‘SilverStar’ Halogen Headlight Bulb P/N 9003ST. Much brighter than the stock bulb. It has worked great for the last 1 year.

Bought it from AutoZone for $19.95 a year ago.

Harley has a high output halogen that replaces the stock bulb, don't remember the part number but I do think it was competitve with the Silverstars in cost. Amazing that H-D has a part that is competitve in cost with anyone.

By the way I've had a set of Silverstars in my GrandAm for over 2 years now and still going.

Ohms Law, Watts divided by volts equals Amps.... I don't know what the wires are rated for, but at 65 watts you are pulling 5.41 amps.

:wonderlan I've read several opinions on "up-ing" the lights. The stock is 55/65 I think and they make several more powerful lights but as has been mentioned "heat" becomes a factor. I've read that a good compromise is the 85/100. I can't recall which brand I switched to other than it was said to be a "German Touring" bulb (H4 - 85/100) it was $14 I think and it is a BIG improvement over the stock light. :tour The focus/pattern is much more consistent and the light output is clearly brighter:tour . Now, as of yet I've not "melted" my wires but as I would often run my :tour "brights":tour during the day I've compromised and just run the "low" beam unless I need the brights at night. I'm very pleased with the light out-put and pattern (IMHO) much improved from the stock set up, with any luck I won't fry my wires.

:tour Rick:tour

The Harley replacement bulb referred to above is $19.95 and it works well. I have been using it for about a year. Much better than the stock bulb.

Fred

I think it usually happens from vibration, causing small arcing, causing corrosion, causing heat, causing melted plastic.

Gazza[/QUOTE]
looking back through old threads to find ideas why my fuse keeps blowing
do you think this could cause my fuse to keep blowing there is corrosion on my fuses and fuse block ,probably from over washing { at least once a week }
my thoughts water+vibration=arcing=corrosion=HEAT=blown fuse????????

I replaced my stock headlight bulb with a Osram-Sylvania ‘SilverStar’ Halogen Headlight Bulb P/N 9003ST. Much brighter than the stock bulb. It has worked great for the last 1 year.

Bought it from AutoZone for $19.95 a year ago.

Just looked at them yesterday and the price is the same!!! Getting this one myself along with the H3 versions for the spots.....:gun

Wanted the Sylvania Silver Star but could only find them packaged as two. $38 for two.

Went with Sylvania Cool Blue for $9.00. Just one step below the Silver Stars.
It's much brighter than stock and I'm happy.

anyone out there running with Sylvania cool blue 9003 cb and what were your results?

anyone out there running with Sylvania cool blue 9003 cb and what were your results?
----------------------

I wanted something better than the stock lamps. Wanted to try Silver Stars but the store only had packages of two for $38.

I went with the 9003 CB (Cool Blue). Price was $9.xx for one. Thought the price was right for trying.

Big improvement over stock! Give them a try, you'll probably like them.
I'm happy.

Ohms Law, Watts divided by volts equals Amps.... I don't know what the wires are rated for, but at 65 watts you are pulling 5.41 amps.

Your post is almost correct.
Watts divided by volts equals amps is correct.
But it has nothing to do with ohms.
Ohms is a resistance measurement.
Also your calculation of 65 watts equals 5.41 amps is based on 12 volts.
If your voltage is only 12 with the motor running its not charging.
13.6 +- is nominal.
So doing the same thing with 13.6 would come out to 4.78 amps.

Your post is almost correct.
Watts divided by volts equals amps is correct.
But it has nothing to do with ohms.
Ohms is a resistance measurement.WHAT !!!!

It has everything to do with ohms. You can have a gazzillion volts and stil have zero power cunsumption (watts) if the resistance is high enough.

P = V x I
I = V / R
therefore:
P = V x V / R

Anyway the resistance of the bulb is more of a constant than the wattage. The resistance changes slightly as the bulb heats... but that's not a big deal.

When a bulb is rated for a certain wattage, it's always done so at a particular voltage... i.e. 65 watts at 12 volts, or 65 watts at 14 volts.

The math everyone used up above, I = P / V, gives you a good ballpark current requirement for the bulbe and wiring leading up to it. BUT if you want the exact current you need to know the bulb restance and the running voltage of the electrical system.

You can get more than 65 watts out of a 65 bulb or less than that depending on the voltage applied.

Gazza

The wiring leading up to the headlights is all 18 gauge wire.
According to this AWG wire rating table (http://www.powerstream.com/Wire_Size.htm) thats good to 16 amps.

Which is a real good thing that it's slightly more than the fuse rating. We don't want a lot of wires only rated for 10 amps on a 15 amp fuse otherwise the wires could catch on fire with a short.

Note that the wires going to your idiot lights are all 20 gauge. They can only handle 11 amps, and they are on the same 15 amp fuse. So they have the potential to melt, but those bulbs are pretty high resistance so they don't take much current or consume many watts ;)

Gazza

WHAT !!!!

It has everything to do with ohms. You can have a gazzillion volts and stil have zero power cunsumption (watts) if the resistance is high enough.

P = V x I
I = V / R
therefore:
P = V x V / R

Anyway the resistance of the bulb is more of a constant than the wattage. The resistance changes slightly as the bulb heats... but that's not a big deal.

When a bulb is rated for a certain wattage, it's always done so at a particular voltage... i.e. 65 watts at 12 volts, or 65 watts at 14 volts.

The math everyone used up above, I = P / V, gives you a good ballpark current requirement for the bulbe and wiring leading up to it. BUT if you want the exact current you need to know the bulb restance and the running voltage of the electrical system.

You can get more than 65 watts out of a 65 bulb or less than that depending on the voltage applied.

Gazza


Let me clarify a little.
I will give you that ohms does play a major factor in determining the bulb wattage. But since that had already been determined as being a 65 watt bulb then it need not apply again.
So saying watts divided by volts equals amps has nothing to do with ohms.

Let me clarify a little.
I will give you that ohms does play a major factor in determining the bulb wattage. But since that had already been determined as being a 65 watt bulb then it need not apply again.
So saying watts divided by volts equals amps has nothing to do with ohms.

My point is that resistance matters more, the wattage is not constant, and that the 4.78 amps calculated from the 13.6 volts is wrong. The proper way would be to work through using resistance.

If the bulb is rated 65 watts at 12 volts then...
R = V * V / P = 144 / 65 = 2.22 ohms

So current at 12 volts is:
I = V / R = 12 / 2.22 = 5.4 amps

And the current at 13.6 volts is:
I = V / R = 13.6 / 2.22 = 6.13 amps

Not 4.78 amps. Using resistance properly in the math shows that the current draw actually increases as the voltage increases which is obvious day one stuff. When you use the back of the napkin calculation of I=P/V then you get erroneous results.... in your calculations current dropped when the voltage was raised which just doesn't make any sense at all.

So in reality the power is not constant...
If this bulb is rated at 65 watts at 12 volts it will consume 83 watts at 13.6 volts.
Ever notice how your light gets brighter when you start the engine?
That's because... you guessed it... you're putting more power into the bulb at the higher voltage.

Gazza

Enough!!! The point is that the wires are well below their amperage rating and that the plastic clip is the culprit for failure and that Silverstars or blue bulbs are the best choice per dollar.

Here you go - cheap and it works better than any 'blue' 'xenon' etc. I have tried on anything (car, snowmobile, bike).
NAPA sells a 80/100 H4 bulb for off road use only - for less than $15. Made in Germany - Osram I think was on the bulb.
Whitest brightest - huge difference on that Sporster headlight.

I will let you all know when it melts down or burns out in my 05.

I put a 55/85 bulb when the bike was new in 98, it's still there and works great, really lights up the road. It was a generic bulb with no mention of the manufacture.


Crim tried a high output one on his 99 model and kept melting the the socket. Did the socket change from 98 to 99 ? I don't know but mine works great!