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Old 07-28-12, 10:45 AM   #1
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A few dynamo questions?

I recently acquired a bike with a dynamo generator, rear and head lights. The wiring looks shot, and I am unsure of how to test the equipment, in the IT world I'd just use known good parts with the generator first.. but as I have no dynamo stuff I have no known good stuff, would a power meter work? If the generators good I'm sure I'm going to have some more questions, so I apologize if this is kids stuff to you guys. Any idea for how I should check that the generator works?
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Old 07-28-12, 10:58 AM   #2
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If you have a multimeter, sure, use that on the generator to check for voltage output (technically AC, but the main point is there's *something*). You can use the continuity test feature or electrical resistance feature (ohms) to check wires for electrical continuity. From the nature of your question, I'm guessing the system isn't working presently?
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Old 07-28-12, 11:56 AM   #3
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I've never tried just putting a voltmeter across a generator, but I would guess it should work. You can also test the wiring for open condition. My guess is that your bulbs are shot, assuming you have bulbs
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Old 07-28-12, 05:48 PM   #4
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If you have a multimeter, you should be able to read the voltage coming from the dynamo when you spin the wheel - measure AC voltage, and you should see ~6V or so - different dynamos give slightly different voltages, and the voltage will change with the speed at which the wheel is spun.

If the lights are incandescent type (not LEDs), then you can switch your meter to resistance, and measure the impedance of the lights - if a light is burnt out, the resistance will be very high (over 1,000 Ohms), if it is not burnt out, it will be quite low - less than about 10 Ohms.
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