12 volt conversion

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12 volt conversion

Postby Eamonn » Fri Feb 15, 2008 7:36 am


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12 volt conversion

Postby Eamonn » Fri Feb 15, 2008 7:40 am


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12 volt conversion

Postby Eamonn » Tue Jan 13, 2009 11:05 pm

An article specifically for Lightweights can be found here:

Click on this link for 6v to 12v conversion
http://www.ajs-matchless.com/article_read.asp?id=507

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12 volt conversion

Postby Rob Harknett » Wed Dec 29, 2010 10:56 pm

I just had a quick peep at this topic. I only clicked on the coversion page, where it details parts required, to convert from 6v to 12v.. Its not good, could cause a fire?? The parts required need to be corrected. You really should change the 6 volt horn to a 12 volt horn. Rob Harknett

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12 volt conversion

Postby greasemonkey62 » Sun Jan 02, 2011 2:43 pm

I did a 12 volt conversion after lots of detail searching as I was uncertain if I should attemp it myself, I decided to have a go and found if done with care and time it was not too difficult at all, I got a 200 watt alternator from Paul Goffs that was a straight swop with the old one and a Boyers conversion kit complete with an induction discharge unit which allowed the points to remain in operation and pitting reduced dramatically, the bike looks no different to before the changes as the 2 tiny boxes are in the toolbox, but I have a bike thats starts first kick, ticks over superbly and a headlight more powerful than my newish car, a winning combination and well worth the initial headscratching.

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12 volt conversion

Postby greasemonkey62 » Sun Jan 02, 2011 2:46 pm

P.S. My bike is a 1962 AJS model 31 650 twin.

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Re: 12 volt conversion

Postby alanjennings » Fri Nov 15, 2013 5:17 pm

Rob, I've run a6 volt horn on my V-----t, converted to12 volts, for nigh on 30 years and never had a problem!-famous last words!
Alan [Morini] Jennings

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Re: 12 volt conversion

Postby Colin F » Fri Nov 15, 2013 5:50 pm

The problem with a 6 volt horn on a 12 volt system is that although it will work the resistance factors are wrong and can lead to the wire in the windings breaking down.
If they break and go open circuit (in other words the wire breaks and the ends are not touching) no current will flow and the horn will not work.

However if the wires break and are still touching they will start generating heat, fusing more and more of them together, drawing more current and in the end could catch fire (especially if there is no fuse in the circuit).

The real problem would come if your insurance company sent out an assessor and he noticed a 6 volt unit on a 12 volt system you would be very unlikely to get a pay out! :headbang:

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Re: 12 volt conversion

Postby Julian_S » Fri Nov 15, 2013 6:17 pm

Colin F wrote:The problem with a 6 volt horn on a 12 volt system is that although it will work the resistance factors are wrong and can lead to the wire in the windings breaking down.
If they break and go open circuit (in other words the wire breaks and the ends are not touching) no current will flow and the horn will not work.

However if the wires break and are still touching they will start generating heat, fusing more and more of them together, drawing more current and in the end could catch fire (especially if there is no fuse in the circuit).

:


Given that a horn is only used for a few seconds at a time the chances of that happening would be significantly less than winning the euro millions. Sounds like a job for Mythbusters.....

The worst think that will happed is that it will just pack up.

Julian

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Re: 12 volt conversion

Postby billbeavis » Sat Nov 16, 2013 1:13 pm

At the time I converted my alternator single to 12 volt I had also read it was suggested to keep the 6 volt horn so did just that. Initially it worked so I kept it. Then one night after leaving club meeting, a pal tooted in parting of our ways. I did the same only for the bike to stop on a dark country road. Turns out the horn failed and blew the one fuse I had in the loom. Not a big deal as I had spare fuses but it didn't take long to get a 12 volt horn after that. It was cheap and sits under the seat so can't be seen. Now I have one main fuse, one brakelight switch fuse and one main fuse. That way if the horn or rear brakelight fail short, the 'bike doesn't stop. Incidently I had a few years previously also converted a beetle to 12 volt and left the 6 volt horn in place. That had to go too eventually. :beer:

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