Wiring a sidewall dynamo
12-31-18, 11:38 AM
#1
Senior Member
Thread Starter
Wiring a sidewall dynamo
I posted this in the mechanics subforum but was directed here.
A previous owner of this bike put a sidewall dynamo and light on it, but it is not connected. I have never seen one of these (up close) and have no idea how to connect it. Like absolutely no idea, so I apologize for being completely clueless. I'm attaching some pictures and I hope someone can point me in the right direction. The dynamo has 4 connection points and a short wire. The light has 4 connection points, 2 labeled IN (+ and -) and 2 labeled OUT (+ and -.) Then there's a double wire (one black and one with a white stripe) to attach the light to the dynamo. My attempts to connect this have so far not worked ... for all I know maybe the light doesn't even work. How do I hook this thing up? It would be cool if I could actually get it working.
By the way this seems to be instructions for this light but all it says is "The cable coming from the dynamo must be connected to the terminals of the headlight that are marked “in”" (which is not that helpful)
https://en.bumm.de/fileadmin/user_upl...C_Lyt_2012.pdf
A previous owner of this bike put a sidewall dynamo and light on it, but it is not connected. I have never seen one of these (up close) and have no idea how to connect it. Like absolutely no idea, so I apologize for being completely clueless. I'm attaching some pictures and I hope someone can point me in the right direction. The dynamo has 4 connection points and a short wire. The light has 4 connection points, 2 labeled IN (+ and -) and 2 labeled OUT (+ and -.) Then there's a double wire (one black and one with a white stripe) to attach the light to the dynamo. My attempts to connect this have so far not worked ... for all I know maybe the light doesn't even work. How do I hook this thing up? It would be cool if I could actually get it working.
By the way this seems to be instructions for this light but all it says is "The cable coming from the dynamo must be connected to the terminals of the headlight that are marked “in”" (which is not that helpful)
https://en.bumm.de/fileadmin/user_upl...C_Lyt_2012.pdf
12-31-18, 04:44 PM
#2
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Location: Peoria, IL
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gee... this makes me appreciate my hub dynamo even more... just two connector terminals on it, so there's no way to mess up.
The dynamo wire that is connected to the mounting bracket looks like it is intended to allow you to connect one of the dynamo terminals to the frame. The frame connection is sometimes used to carry electrical current. Personally, I prefer to just use wires, so I wouldn't hook it up to anything.
Are there any markings at the dynamo terminals?? My guess is that these are two sets of connections, and you only need to hook up to one set. Are there any indications of which terminals are electrically connected together within the dynamo?
My guess is that the rib that is in the middle of the four terminals separates the "plus" terminals from the "minus" terminals (and since this is AC, there isn't really a plus or minus, but it keeps the terminology simpler). I'd try connecting one wire to a terminal on the left of the rib, and the other wire to the right of the rib.
If that doesn't work, try connecting the wires on just one side of the rib.
At the light, just run the wires into the "in" terminals. The "out" terminals are used to connect to the taillight.
Steve in Peoria
The dynamo wire that is connected to the mounting bracket looks like it is intended to allow you to connect one of the dynamo terminals to the frame. The frame connection is sometimes used to carry electrical current. Personally, I prefer to just use wires, so I wouldn't hook it up to anything.
Are there any markings at the dynamo terminals?? My guess is that these are two sets of connections, and you only need to hook up to one set. Are there any indications of which terminals are electrically connected together within the dynamo?
My guess is that the rib that is in the middle of the four terminals separates the "plus" terminals from the "minus" terminals (and since this is AC, there isn't really a plus or minus, but it keeps the terminology simpler). I'd try connecting one wire to a terminal on the left of the rib, and the other wire to the right of the rib.
If that doesn't work, try connecting the wires on just one side of the rib.
At the light, just run the wires into the "in" terminals. The "out" terminals are used to connect to the taillight.
Steve in Peoria
12-31-18, 06:07 PM
#3
Senior Member
Thread Starter
Hey you're right, I didn't even notice before because it's not that easy to see, but there are markings. Looks like a "ground" symbol for the 2 connectors on the left and a "live" symbol for the 2 on the right.
So I tried connecting the white wire on the ground side and the black wire on the live side ... they are connected to the minus and plus terminals on the light respectively. Not working though.
So I tried connecting the white wire on the ground side and the black wire on the live side ... they are connected to the minus and plus terminals on the light respectively. Not working though.
01-01-19, 05:34 AM
#4
Junior Member
I guessed from the pictures that the generator is a B&M Dymotec 6. English-language instructions here: https://sjscycles.com/Instructions/Bu...structions.pdf The document suggests that is a straightforward AC generator, so really this should "just work".
Some things to try:
1. I apologise if this seems insulting, but did you try all positions of the headlamp switch?
2. Try connecting the wires at the generator both ways round.
3. Remove the ground wire at the generator.
The reason for 2 & 3 is that there seems no reason for a ground wire when connecting with two wires. The instructions confirm that.
(They say "mass" for ground: poor translation from German.) If there is also a ground (frame) wire in the lamp, the problem could be
a short circuit.
If none of that helps, you need to do some systematic troubleshooting, as any of generator, lamp and wires could be faulty.
Do you have any kind of electrical test equipment? At a minimum, some (different) wires, the batteries and bulb from a torch/flashlight
and lots of hands will do. Alligator/crocodile clips help a lot.
Some things to try:
1. I apologise if this seems insulting, but did you try all positions of the headlamp switch?
2. Try connecting the wires at the generator both ways round.
3. Remove the ground wire at the generator.
The reason for 2 & 3 is that there seems no reason for a ground wire when connecting with two wires. The instructions confirm that.
(They say "mass" for ground: poor translation from German.) If there is also a ground (frame) wire in the lamp, the problem could be
a short circuit.
If none of that helps, you need to do some systematic troubleshooting, as any of generator, lamp and wires could be faulty.
Do you have any kind of electrical test equipment? At a minimum, some (different) wires, the batteries and bulb from a torch/flashlight
and lots of hands will do. Alligator/crocodile clips help a lot.
01-01-19, 12:27 PM
#5
Senior Member
Thread Starter
All right, I am ready to conclude that there is some nonfunctional part in this setup, and it's not just that I'm an idiot and can't wire it correctly.
Thanks for finding those instructions. It does seem like it should be straightforward and there doesn't seem to be anything I have connected wrong.
I'll see if I can find some alligator clip wires and do some troubleshooting ... thanks for your help.
Thanks for finding those instructions. It does seem like it should be straightforward and there doesn't seem to be anything I have connected wrong.
I'll see if I can find some alligator clip wires and do some troubleshooting ... thanks for your help.
