[07Fatty]

I have an 07 fatboy with passing lamps. Harley says to use the factory 35 watt h-3 bulb or it could hurt something everywhere I check except Harley, only offer a 55 watt bulb . Harley cannot tell me what may happen. I have already added a PIIA replacement headlight bulb, and i don't want to draw to many amps on the circuit . Has anyone else done bulb upgrades and/or had any issues?

[fujimo]

hd tells you the dumbest junk,,,, told me to go to napa and get bulbs for lower legs,,,, said 194,,,,NOT ,,,, they werent even close,,,, pops

[SPORSTERBOY]

DON'T KNOW ABOUT YOURS BUT ON MINE IT'S THE SAME BULB THAT IS IN MY TAIL LIGHT, 2 FILIMENT, RUN AND BLINK, I WOULD SAY GO WITH WHAT FITS, DON'T THINK THAT A LITTLE BULB BLINKING COULD DO DAMAGE, OR JUST DO LIKE I DID, YANK'EM ALL OFF AND USE YOUR HAND JUST CAUGHT ON, WHATS A PASSING LAMP?

[wvak47]

Passing lamps would be the two on either side of the headlamp you see on a lot of bigger bikes. Not what you would think huh

07Fatty here is a link that gives specs for an H3 35W lamp. It also gives other numbers it is known by. I sure as the world wouldn't buy them from Don as he is WAY too high on everything. But atleast it gives you more information of things to look for. Hope this helps.

H3 12V 35W PK22S ECE - H3/12V/35W/PK22S ECE - halogen light bulb lamp - donsbulbs - light bulbs lamps valve valves tube tubes

[Art_NJr]

I have an 07 fatboy with passing lamps. Harley says to use the factory 35 watt h-3 bulb or it could hurt something everywhere I check except Harley, only offer a 55 watt bulb . Harley cannot tell me what may happen. I have already added a PIIA replacement headlight bulb, and i don't want to draw to many amps on the circuit.

Remember this simple rule: "Volts x Amps = Watts." In other words, if you want to run a 60-watt light on a 12-volt circuit, it'll take 5 amps to do it.

Your '07 Fatboy's charging system should be easily capable of running higher wattage lights - just have to remember that they will get hotter. I've got older Sportsters & that is a problem - the charging system won't handle much & a lot of the wiring harness is in the headlight bucket - put a 100-watt headlight in & you'll cook the wiring :-(

Heated handgrips, heated vest for winter riding, etc., the charging system can barely handle it & won't handle several add-ons running @ the same time - although the '04-up Sportsters have a higher output alternator. But you should not have those problems with your '07 Fatboy.

[hotroadking]

I run the 55w sylvania silverstar H3ST bulbs on my Heritage, never had a problem melting wires etc. They are bright white and make a difference and they should at $20 a pop.

You can get standard 55W non silverstar for much less at the auto store.

I also run the Silver Star H4 on the main headlight, it's a significant improvement over the stock yellowish bulb

Remember when they went from standard bulbs to halogen bulbs and we thought they were really white and bright?

Now the silverstars are so much whiter

Then you have HID. Which by the way pulls less amps and puts out more light than a halogen. For more bucks LOL

[chucktx]

Originally Posted by Art_NJr

Remember this simple rule: "Volts x Amps = Watts." In other words, if you want to run a 60-watt light on a 12-volt circuit, it'll take 5 amps to do it.

Your '07 Fatboy's charging system should be easily capable of running higher wattage lights - just have to remember that they will get hotter. I've got older Sportsters & that is a problem - the charging system won't handle much & a lot of the wiring harness is in the headlight bucket - put a 100-watt headlight in & you'll cook the wiring :-(

Heated handgrips, heated vest for winter riding, etc., the charging system can barely handle it & won't handle several add-ons running @ the same time - although the '04-up Sportsters have a higher output alternator. But you should not have those problems with your '07 Fatboy.

i wonder if ya have an easy formula to find amps???? lets say ya have a 300 watt 12volt bulb.....how many amps????

[AFNurse]

Originally Posted by chucktx

i wonder if ya have an easy formula to find amps???? lets say ya have a 300 watt 12volt bulb.....how many amps????

if it is anything like math that I know....if you have a formula, and some of the numbers, you can figure out the one that is missing..... so in THEORY (and I may be WAY off on this, but by simple math alone....) 300/12 should give you amps....should be about 25 amps....

[Art_NJr]

i wonder if ya have an easy formula to find amps???? lets say ya have a 300 watt 12volt bulb.....how many amps????

Same formula - Volts times Amps = Watts, so Watts divided by Volts = Amps. In that case, you'd be pulling 25 amps. Now there is another factor & that is Resistance, so it does get more complicated, but the basic rule is V x A = W.

AFN is correct - if you know 2 of the 3 values, you can figure out the 3rd.

[chucktx]

cool, got it!!!!!!!!!
thanks

[Dakota]

I checked wire size on my bike and it was sufficient to run the 55W passing lights. They sure make a difference. My wife's deluxe had the 35w bulbs but also had plastic reflectors so we changed to the glass reflectors and then put in the 55w bulbs. The plastic reflector shells put off some type of vapor or whatever that fogs the inside of the lense.