brake light on 6v

I recently purchased a 1978 motron and after a few days, got it running. i need a brake light for it and i was thinking about putting a trailer light on it. my question was if a 12v trailer light would work on what i think is a 6v system, and how well it would work. thanks

Re: brake light on 6v

no a 12v light wouldn't would burn out.

Re: brake light on 6v

Maybe I'm not getting this, but why would it burn out? Wouldn't it just be too dim? I can see how a 6 volt light on a 12 V system would burn out, but not the other way around.

You could use any light you want, as long as you replace the 12V bulb with a 6V bulb. In my experience, though, trailer lights use a single double filament bulb. If you're adding a brake light to an existing tail light, you might not want that. Or you could get rid of your tail light and use the trailer light for both?

Re: brake light on 6v

well, try it with a 6v bulb...all i know is that i've tried 12 volt stuff on 6 volts systems before and it hasn't worked....nothing awful will happen if you just try different stuff out though.

Re: brake light on 6v

nathan where can i get me some of that crack yur smokin.

a 12 volt wont burn out. however, the light output wont be strong enough. you really need a 6 volt bulb.

Re: brake light on 6v

i have a "6V" bike and use 12V bulbs.. easy to find and cheap.. and they don't seem to burn out.

pick a 12V of twice the wattage of the recommended 6V..

Like if it's a 6 volt / 10 watt, pick a 12V / 20 watt, or something close. Doubling the wattage keeps the load on the magneto pretty close to what it would be with the 6V.

The 12V bulbs have a thicker element and don't burn out as easily.

btw.. Stick a volt/multimeter on the tail light socket and rev the engine up.. you'll notice that voltage rises with RPM. My bike gets near 30 volts at the tail lamp at top rpm.

Re: brake light on 6v

i always thought a 12v bulb would work too but when i tried it it just burned out after a day. anyhow it doesn't matter. as long as his light works.

Re: brake light on 6v

Joe, where do you get bulbs that have the wattages on them? All the bulbs I see don't have any wattages on the packaging or the bulb. They just have numbers like 5412 and the like.

Re: brake light on 6v

just a small local autoparts store..

Bulb wattage is no secret, although most people don't care, and just buy them by the replacement number/type, like #1156 ..

The 1156 is single element, 21 watts.

The 1157 is dual element.. a 21W(stop lamp) and a 5W (tail lamp)

ask the guy at the parts counter .. or try different stores.

"here's a page with some common dual-element bulbs and wattages .. also candle-power ratings":

" is from one manufacturer's bulb specification guide..."

Notice they are all close to the same wattage .. standard auto bulbs..

Although all this little stuff adds up in terms of maximum load on the magneto, there's no need to get too precise or technical with this .. just find a 12V bulb that fits the socket and is bright enough for government work..

A head lamp might be a different story. They use lots of electricity.

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