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Main fuse blowing, is it a voltage regultor?
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Author:  Mitso [ Sun Jul 16, 2017 5:07 pm ]
Post subject:  Main fuse blowing, is it a voltage regultor?

Hi, need some help with my CRF230F, out riding the other day and it kept blowing the main fuse by the battery. I could see from my Trail Tech instrument panel that the voltage was fluctuating widely, from about 8v-20v. I guess that's what was blowing the fuse.
I don't think its the battery as when I replaced the fuse it started ok. I could bump start it when I had run out of fuses and voltage with a blown fuse was between 0v-3v.

Where do I start looking?

Author:  smokinrider [ Sun Jul 16, 2017 6:51 pm ]
Post subject:  Main fuse blowing, is it a voltage regultor?

Check for a short in a wire first.
Then check the rectifier is working.

I suspect the trail tech isn't that accurate so a fluctuating voltage with a blown fuse is probably zero volts and some interference.

8-20 sounds like a loose wire which might also have been the cause of the fuse blowing.


Start simple and progress from there.

You'll need a multi meter which shows resistance and volts both ac and dc.

You should/may have 3 yellow wires 1 black and 1 green from the rectifier going back to the generator. The 3 the same colour will be the phases from the generator the other 2 will be earth and feed to either the battery or the regulator if it's not integral to the rectifier.

Someone else or the manual can tell you the resistance readings you'll be looking for, for both the generator and the rectifier. From memory the rectifier just needs all the yellows to be one way with the green. (ie when you swap the probe wires from the meter back to front you get no reading, proving the diodes all work) if there's no reading both ways then that'll be an issue.

Each yellow wire to the generator will give a fixed resistance with earth/ground. They should all read the same.
If they're open circuit (no continuity at all) or closed circuit (no resistance, ie shorter straight to earth) it'll be that.

Firstly You could also try starting the bike with the battery disconnected and seeing what you're getting volt wise and if it's ac or dc. Again if it's ac it's the rectifier blown if it's dc and over 20v when you rev it then it'll be the regulator. But bear in mind that if the volts are higher then the amps are lower so that shouldn't blow a fuse.

Remember ohms law. I=V/R. As your draw (R) is your constant an increase in volts (V) will result in a decrease in amps (I)


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Author:  Bill_Mc [ Sun Jul 16, 2017 7:03 pm ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

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Author:  Bill_Mc [ Sun Jul 16, 2017 7:12 pm ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

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Author:  smokinrider [ Sun Jul 16, 2017 11:48 pm ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

From the look at that it's only 1 phase from the generator so you won't have 3 wires the same colour just 1 white one.

Thinking on this more, I'm sure any issues with rectifier would fry the battery rather than blow a fuse. I'd spend a bit of time checking for a short.




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Author:  Bill_Mc [ Mon Jul 17, 2017 10:24 am ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

.

Author:  smokinrider [ Mon Jul 17, 2017 10:40 am ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

Bill_Mc wrote:
It can also be starter/relay pulling too much current if it blows only when starter is pressed, had this before but if it happens when riding then more likely wiring short to earth.



That's what happens on my husky from time to time after over vigorous power washing of the solenoid.


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Author:  mancchair [ Wed Jul 19, 2017 11:04 am ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

Remember ohms law. I=V/R. As your draw (R) is your constant an increase in volts (V) will result in a decrease in amps (A)???????
No it won't !

Author:  smokinrider [ Wed Jul 19, 2017 11:45 am ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

12 amps at 12v is 144 watts. 144 watts at 18v is 8amps. 144 watts at 6volts is 24 amps.

It's the voltage that's claimed to be unstable in this case.




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Author:  mancchair [ Wed Jul 19, 2017 12:01 pm ]
Post subject:  Re: Main fuse blowing, is it a voltage regultor?

Where do watts fit into ohms law ?

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