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Discussion Starter · #1 ·
Hello, I have a strange problem. My tail light will blow within 15 minutes of driving and even the stop light will blow after a while. Once with an brand new light the bike wasn't even started and pressing on the brake, the brake light blew instantaneously. I hadn't even left the parking lot yet! I've changed the lightt 3 times already thinking I had bought crappy lights after blowing the two lights I had just bought I went and got a LED light and it also blew up.
I thought at first this could be a voltage spike that would blow the light but other lights on the bike work fine.
I also thought this could be a ground problem since I noticed there was a missing bolt on the tail light assembly. I thought this could make the light burn up but taking it out let me to notice it's all plastic and there's a third wire for the ground.

So I'm a little clueless as to what might be the problem.

The bike is a 2000 Yamaha V-star 650.

Thanks,
 

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Without looking at your bike I'd guess that you have a short to ground, most likely somewhere from the rear brake light switch back. If you're not comfortable using a multi-meter and checking for shorts you could try just following the wires from the rear brake light switch and look for any damaged of frayed wires. Often they'll develop problems under the rear fender or where they pass through a frame opening.
 

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Hello Fred,

When you say your tail light will blow, you mean bulb . . .right ? not the circuit for tail light and brake-light ?
I was thinking at first it was the fuse, which would have made more sense, insulation worn in one spot and
touches ground but bulbs just blowing, It makes some sense I guess if tail light is mounted directly with no sort
of sponge gasket so road shock and/or vibration can be absorbed instead of going to the bulb, but if bike is not
moving. I guess a real cheap-ass bulb would do that, If it is an 1157 a common tail /brake-light bulb see if you
can get one that is a 'heavy duty type, if you still have trouble go to a dealer and ask if service can take a look,
and explain what's going on.
 

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Without looking at your bike I'd guess that you have a short to ground, most likely somewhere from the rear brake light switch back. If you're not comfortable using a multi-meter and checking for shorts you could try just following the wires from the rear brake light switch and look for any damaged of frayed wires. Often they'll develop problems under the rear fender or where they pass through a frame opening.
Hello 'Eye'
Maybe Monday is messing me up, I don't honestly know if he means bulb blows or fuse for that circuit blows. I
did mention it made more sense for the fuse to blow than the bulbs, with a wire whose insulation got scraped off
and touched the frame. Seems he has trouble with the tail light as well.
 

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I guess I was reading in a hurry too, as fuse what I was thinking. Still, since it happened once after he powered the circuit by using the brake I think that branch is where the problem is.

Wrong fuse in the holder? (Too high amps?)
 

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So Fred. What exactly IS happening? Light bulb keeps burning out on tail light or brake light or both or Fuse keeps blowing?
If fuse keeps blowing when you hit rear brake pedal, then there is a SHORT after the rear brake switch. This is possibly why
tail light gives trouble as both wires would be close together to begin with. You will have to take the time to follow wires to
tail/brake lamp to see if insulation has been worn away where wires pass through the frame or maybe they are touching the
ground wire.

I would suggest you fix this before you ride., not having a tail lamp at night is bad, so is not having a brake light.
 

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MOD / Rider / Mechanic
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Too many volts, check you voltage regulator. Betcha when you hit 3k it jumps over 18volts.
 

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Hello Aphrodite, I don't know what to make of it. Fred Lemire says, "My tail light will blow within 15 minutes of driving and even the stop light will blow after a while. Once with an brand new light the bike wasn't even started and pressing on the brake, the brake light blew instantaneously." Almost sounds like the wrong voltage or type of bulb used.

Fred, check owners manual and see if they list bulb type and check if you have that bulb in the tail-light/brake-light.
 

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Humn... Missed that yeah but still check battery residually can hold more that 12 volts very odd though to fry up LED too generally they can handle up to something like 30 volt dc.
 

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Aphrodite beat me to it. The charging circuit also powers the lights IIRC. So check the voltage at the battery with the bike running and at 3000 RPM or so.

Anyway, it is the quickest test to make, so try it first.
 

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Discussion Starter · #11 ·
Hello all, thanks for your answers. I was talking about the bulb and not the fuse. I,m sorry english is my second language so I might be writing some things wrong.

I bought a pack of 2 bulbs 1157 bulbs and as I said the first one blew instantly in my garage. When I hit the brake the light went very strong and blew instantaly like a flash from a camera. I though at first this was a faulty bulb from factory as I've seen this on my travel trailer once.

The second one worked fine for a few hours but when I got home, both tail light and stop light elements where fryed.

I went back to the store and bought 2 LED lights (for 24$!!!). Installed it on my bike, was working fine. Went to work (20 minutes drive) and the tail light was blown already.

I'll try to get the voltage on a multimeter but I will also take apart the socket to see if there wouldn't be any shorts.

Other than that my guess is that I will need to remove the back wheel to follow the wiring. Seems a bit complicated.

Thanks all.
 

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Well, Aphy might be right about voltage, that is if the bike WAS running, the R/R can screw up in one of two ways,
not enough volts for charging battery or too damn many of them, but that would be for the 1157's No idea what the
IIRC is but I also heard that LED's were good for around,30 volts, probably why they are good for those BIG RIGZ
as they I'm sure have a 24 volt system.

Actually I had this problem, partly. The brake-light switch for front brake broke and brake-light was on a lot, I saw
that doing my pre-ride check, 1 bulb a week, like damn that's a bright tail-light! When it blew, it wasn't just the
filament you could see as parted, the whole bulb was 'smoked' could not see anything. I always keep a few spare
bulbs in my fork bag, so if one bites the big one, no need ta rush out an buy one.
 

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Don't know where you are at but here you can buy heavy duty bulbs that resist vibrations better. But you said one blew before you rode so that may not be it either.
 

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Discussion Starter · #14 ·
Don't know where you are at but here you can buy heavy duty bulbs that resist vibrations better. But you said one blew before you rode so that may not be it either.
That one could have been a manufacturing defect.

The other times I did drive on the highway and my bike does shake a lot on highway speed (see my other thread in the beginners section).
 

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Discussion Starter · #15 ·
I went to the auto part store to get heady duty bulbs and the guy told me that motorcycle bulbs have a lower watts rating than regular car light bulbs.

He says this could have something to do with my problem.

Since I went and bought my lights in the automotive section of Walmart, I am going to go to a motorcycle show to get the right light bulb. It can’t hurt I guess…
 

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Discussion Starter · #16 ·
Well here is an update one month later. The motorcycle bulb worked fine and it's on ever since.

Lesson here... Automotive lights don't work on the motorcycle even if they physically look the same...
 

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Thanks for the follow up. The filaments are stronger and thicker in the motorcycle bulb.
 

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Hello Fred,

Everyone here wants to help you but you need to be MORE specific, DO YOU mean the BULB itself 'blows out' ?

If so was the bulb darkened or clear. I had an issue with the WG, front brake sw. stuck on and every time I did
a pre-ride one bulb would be out, which was also weird, wrencher said ,"It was on too long, that is why it melted
the red lenz cover."Bulb was NOT clean but very dark.

Aphy mentioned a bad R/R rectifier regulator but that can't be it if the bike is NOT running, if bike was running with
a bad R/R and charge volts were too high, then Aphy would be correct.

If the fuse for that circuit 'blew' meaning it was darkened, than the short would be AFTER the FRONT OR REAR
brake switch since power goes to one side of each switch and brake lamp connected to other side of both switches,
that means the switches are in parallel but in series with the brake-light.

If the fuse is too big meaning its 'AMPS' rating and there is a short, the fuse will NOT BLOW but the wiring will be fryed
and very quickly I will say. If the fuse amps is LESS than load amps, the fuse will open, the link will melt. If the load
is a 5 amp headlight bulb and is in series with a half amp fuse, the fuse could look like it blew on a short circuit, meaning
it was darkened, even though there was no short just that the load allowed the current it would draw to flow through too
small a fuse, Not much different than a BIG 18 wheeler going over a country lane 1/2 ton bridge.

When one wires a bike, they add up the amps for the loads or lights, ignition circuit that will be 'ON' continuously. if it all
adds up to 8 or 9 amps, than I'd fuse the circuit with a 10 amp fuse, anything more than that flows means a 'Short circuit.
causing much more current than is needed to work loads and the fuse will open, Now if on that circuit you added a radio with
a big-ass amp and it drew ten amps, the fuse would most likely open on over load, it could be blackened but not as much as
a sudden surge. if the radio drew 5 amps, the fuse most likely would melt the link and not be darkened at all.

So Fred is it the bulb that 'blew'' or the fuse for that circuit?
 
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