HELP! i added lights and have blown 3 fuses so far

robtaylor · Post by **robtaylor** » Fri Jun 13, 2008 9:33 pm

i added some driving/fog lights to my front forks and they worked for a few minutes when i first hooked them up. then the fuse blew.

i went straight from the battery, to a switch, to a fuse, to the lights. i was worried that the buddy wouldn't have enough juice to power them very well. but if i understand electricity (i probably don't) if the fuse is blowing it means that they are getting too much power right? everything else (starter, headlights, blinkers, etc.) seems to be working fine.

someone that actually understands electric stuff, could you explain why this is happening and if i can fix it or do i have to get rid of the lights?

tunseeker1 · Post by **tunseeker1** » Fri Jun 13, 2008 9:38 pm

how long do they work for when you turn them on?

What lights did you put on? Websites are helpful but all the specs would work too.

What size wire did you use and what size fuse?

illnoise · Post by **illnoise** » Fri Jun 13, 2008 9:48 pm

Too much AMPERAGE (current) is blowing the fuse. The point of the fuse is to blow (it's cheap) before your light blows (it's expensive).

Could be a lot of things, the lights are just not rated for what you're using them for, there's a short somewhere, they're not grounded properly, etc. Do you have a multimeter?

Battery voltage is usually higher than 12v, so it goes through a regulator to regulate the voltage to 12v, so you might need to add a regulator, or run the lights from the regulator already in the bike, or just wire them differently.

Bryan

robtaylor · Post by **robtaylor** » Fri Jun 13, 2008 9:51 pm

when i replaced the first 15A 250V fuse they do not work even for a second when i switch them on. i bought some cheap lights from wal-mart (and threw away the packaging) for 14 dollars and the wiring came with it, i do not know the exact gauge. i think the lights were 55watt. i have looked for them on the web but have yet to find them.

tunseeker1 · Post by **tunseeker1** » Fri Jun 13, 2008 9:59 pm

check all your wiring again. If its instant blowing then they are wired wrong.

illnoise · Post by **illnoise** » Fri Jun 13, 2008 10:06 pm

robonz23 wrote:when i replaced the first 15A 250V fuse they do not work even for a second when i switch them on. i bought some cheap lights from wal-mart (and threw away the packaging) for 14 dollars and the wiring came with it, i do not know the exact gauge. i think the lights were 55watt. i have looked for them on the web but have yet to find them.

Were they designed for a motorcycle? I guess I've never looked at the voltage rating on fuses before, but 250V is 20x the voltage of your battery, that seems weird. Could be normal though, again, it's the amperage you're worried about, not the voltage.

Did they blow out as you revved the engine? The higher you rev the engine, the more juice your battery's getting from the magneto (to charge faster). That unregulated power might just be blowing the fuse.

robtaylor · Post by **robtaylor** » Fri Jun 13, 2008 10:16 pm

they were designed for a car/truck i thought i was weird that the fuse was 250v also.

they blow before i get a chance to rev the engine, if it's running or not.

i suppose i'll go back throught the wiring and make sure they are grounded correctly. i tried to take great pains to make sure i grounded them with connectors that fit under a screw or bolt that are bolted to the frame or the fork.

andgosun · Post by **andgosun** » Fri Jun 13, 2008 10:45 pm

Electronic theory is as simple as amps = watts divided by volts. 55 watt bulbs need 4.5 amps to operate and should be fused about 20% over that. Figuring the Buddy battery @ 7 amp hours, this bulb will deplete the battery in 1.5 hours. Now the alternator will help extend that time, however in my opinion you are demanding a lot from the battery with 1 bulb, let alone 3.

robtaylor · Post by **robtaylor** » Fri Jun 13, 2008 10:53 pm

andgosun wrote:Electronic theory is as simple as amps = watts divided by volts. 55 watt bulbs need 4.5 amps to operate and should be fused about 20% over that. Figuring the Buddy battery @ 7 amp hours, this bulb will deplete the battery in 1.5 hours. Now the alternator will help extend that time, however in my opinion you are demanding a lot from the battery with 1 bulb, let alone 3.

i was warned that i'd be asking a lot of the battery but does this explain why the fuse is blowing? i expected that i'd see an over-all decrease in electric power if i was strainging the battery.

andgosun · Post by **andgosun** » Fri Jun 13, 2008 10:57 pm

One also needs to remember that that theory works as the battery voltage drops - so as the battery voltage is drawn down to 10 volts due to too big of lights for the battery, 55 watts divided be 10 volts , the amperage has now risen to 5.5 amps. If all the wires have good grounds then the lights will draw its full amperage. If however the grounds are not good, the voltage to the bulbs will drop, and the bulbs will dim because the watts still stay the same, the voltage across the bulb will drop. Bulbs also are actually under rated and the actual wattage is greater than advertised. Imported bulbs have a greater varience than USA bulbs.

tunseeker1 · Post by **tunseeker1** » Sat Jun 14, 2008 12:54 am

its simple. You might have pinched a wire under a panel somewhere and the power side is grounding out. Don't worry about anything concerning the battery life until you fix the short.

I would try and run a wire from the fuse holder to a single light and see if it still blows the fuse.

If you have a multimeter check for a short in the wiring after you disconnect the lights from the wires.

MarsR · Post by **MarsR** » Sat Jun 14, 2008 1:02 am

robonz23 wrote:
andgosun wrote:Electronic theory is as simple as amps = watts divided by volts. 55 watt bulbs need 4.5 amps to operate and should be fused about 20% over that. Figuring the Buddy battery @ 7 amp hours, this bulb will deplete the battery in 1.5 hours. Now the alternator will help extend that time, however in my opinion you are demanding a lot from the battery with 1 bulb, let alone 3.
i was warned that i'd be asking a lot of the battery but does this explain why the fuse is blowing? i expected that i'd see an over-all decrease in electric power if i was strainging the battery.

If it's blowing a 15A fuse, there must be a short in the wiring somewhere. A short would bypass the 55W bulb, so the wire resistance (minimal in this case) is the only load and the current will skyrocket. The fuse blowing is keeping the wiring from burning up. I would probably go to a 10A fuse and check your wiring with a multimeter for opens/shorts. It may still be too much load for the battery & generator, but it shouldn't be blowing fuses.

On second thought, is that 2 55W bulbs? If so, stay with the 15A fuse.

luckyleighton · Post by **luckyleighton** » Sat Jun 14, 2008 1:16 am

If it is not a short, you have bought a light that was not designed for your scoot's electrical system.

A fuse is to prevent fire and damage to electrical components (because of a short). If its just a bit more powerful than your old light no biggie, just get a slightly bigger fuse and move on. But if it is way more powerful than your old light you needs to make sure the wire going to the light can handle it, and that may affect your battery life as well.

nissanman · Post by **nissanman** » Sat Jun 14, 2008 2:07 am

Gotta agree with andgosun on this thread... I don't think your buddy can power two additional 55W lights with a stock electrical system. My Rattler couldn't keep enough power to a 4amp ballast for an HID setup, keep in mind that a stock 35W bulb draws about 3 amps. That extra amp was enough to drain my battery every time. Since you wired the power straight from the battery you will get a dead battery before too long. If you powered it up from the Buddy's electrical system they'd work, but be dimmer than intended. A Halogen bulb will only light up as much as it can with it's given power supply (think of a flashlight with low batteries). Hope all this helps