JeffOYB

We have a Breezer Uptown w Shim dynohub. After about 10 rides, the lighting failed. I've never worked on a dynohub. I don't know about diagnosing them. Is there a common glitch to look for?
I haven't done much electro work but i can use probes. or i can check connections wherever they might be. i don't SEE any. i don't see anything that is loose, either. I see some wiring though... maybe the loose part is inside something... it's supposed to be sealed from rain, after all.

tastewar

After 10 rides? Sounds like it ought to still be under some sort of warranty. Have you spoken with the shop where you bought it?

dsbrantjr

That sounds like a warranty repair/replacement. I would check that out before doing something, like opening it up, which may void the warranty. Most dynamos have thin wires inside going to the output terminals which are easily broken if disassembled incorrectly

I would check out the wiring and lamp(s) for continuity, make sure that the connections and grounds are good. The frame is often used for the current return, a mistake IMO, to save 3 feet or wire, and that the dynamo is putting out about (typically) 6V AC. There might be only 1 output terminal, with the axle as return. Check for DC voltage, too, on the off chance that it has a DC output. Watch your fingers, long hair and test leads around the spinning wheel.

Not sure what model you have, but here are some documents which you might find helpful: https://si.shimano.com/#/en/search/Keyword?name=DH-3N30 Substitute your model number in the search if you can find it.

JeffOYB

online purchase ... example of why to buy from LBS ... still it was our first new bike in decades ... we're in the used bike bracket usually

ChinookTx

Not sure what your hub is, but if it's like this, looks for the piece with the grey cap. Wires may simply have come loose. If you have a meter, check the DC voltage while spinning the hub.

alcjphil

Doesn't matter, still a warranty issue. Pursue that avenue before you start trying random repairs

sweeks

The dynohub produces alternating current (AC). If you carefully clamp the wheel's axle in a vise (ideally an axle vise) and connect an AC voltmeter to the terminals, then give the wheel a spin, you should see 8-10 volts (since the hub is unloaded). If you short the terminals together, the wheel will come to a very quick stop... dynamic braking.

EDIT: I agree with those ^^ who said this is a warranty issue. However, if you want a look at a similar dynohub's service, look here: Hubstripping. I suspect that both the Joule I and the Shimano hub are made by Sanyo and bear a number of similarities. More recent Joule hubs are made by Shutter Precision.

AnkleWork

First check the external wiring and switch, if any. Then check the light. Last, check the hub.

Rick

I had a similar problem with my setup. It was the grounding of the headlight. After carefully sanding some of the paint off were the headlight bracket bolted to the fork crown everything was working again.

JeffOYB

thanks everyone!

it was new last august. we'll see about warranty. i'm in discussion w breezer now -- so far it's been circular. my first experience of new product and warranties!

jimc101

You have a 2-year warranty on the hub (https://bike.shimano.com/en-US/infor.../warranty.html), but as others have said, there are plenty of other things to look at before going down this route.

You said the lighting had failed, is it the light, is is the wiring, is it a connector not attached correctly, so many things to look at before just saying the Dynamo hub has failed.

Having read through your post a few times, you do seem fixated on one item being at fault, without checking anything else. You need to find what/where the failure had occurred and work from there for a solution. be it the hub, light wiring, connector etc.

JeffOYB

i can't see how i'd seem to be fixated on anything since i haven't said what i've tried yet. i haven't tried anything yet but will use the ideas in the replies. so far i only reported what happened. from a quick scan everything appears to be attached. all visible wiring looks good and is attached.

i do question the quality of the assembly we got from the shop where the bike was shipped. but that's an hour away. it came to us w wiring that was dangling around a lot. we've taken some measures to tidy up the wiring as best we cd w/o disconnecting anything.

jimc101

The title of the thread? maybe something like 'dynamo lighting system stopped working' it a lot more generic but still asks the same question, the current thread title blinkers everyone into thinking it's the hub at fault before any fault finding has been done.

JeffOYB

oh. sorry. dynohub problem to me includes all wiring, lightbulbs, etc. -- shorter -- get details in post

JeffOYB

I see that the bracket is painted. The crown is painted. I'm not scraping anything. This wouldn't be an intended ground point. So I'm not going to try to make it one. I'll keep looking...

zacster

It is much more likely to be a wiring issue than anything else. Wires break easily. Ground points oxidize. Connectors come loose. Induction OTOH doesn't stop unless the laws of physics change. LEDs last a very long time.

JeffOYB

Here's the latest! I finally looked at the bike more. All the wires appear like new. Connections look fine.

I used a meter on the connection leaving the hub and i got juice! I don't know how to use a meter but i stuck the electrodes in and I got a reading w the numbers in the 3's and 4's range when i spun the wheel. So something is coming out.

Then the wiring disappears into the sealed cheap plastic headlight. Then it comes out of the headlight and there are connections to the rear light wiring which then disappears into the frame.

I unplugged those connections and tested if juice was coming out of the wiring that was leaving the headlight. Zero reading on any setting on the fancy meter. Maybe 20 settings. That's how i do electronics. try everything.

So my guess at this point is that something is bad inside the headlight which i cannot look inside of.

I see Breezer has a 1 yr warranty on components. I bought the bike 11 months ago! I'll just bring it in to the dealer. the performance mail order dudes where i picked it up did a bad job assembling the wiring anyway. it looks fine it just had a lot of excess that's now wrapped around the headtube.

Say, where could there be a ground point? I don't see the possibility. The wiring doesn't 'stop' anywhere that i can see. The headlight bracket is black metal and the fork crown is nice paint. the tail light bracket is silver metal.

Rick

I have a Son SL hub that is why I suggested the paint removal. You have two wires coming from the hub. One is the power and one is the ground. Make sure you have good metal contact at those points. Dissemble and clean the contact points. It is very unlikely that the alternator hub is the problem.

JeffOYB

i just reported that i found juice coming out of the hub. i dont know how ground would factor in there.

On the Shimano there is a plastic click-fitting. everything looks fine. and the fitting clicks into place.

on the plastic headlight is a switch that seems flimsy. nothing comes apart to let me look inside the light.

and it turns out that my local dealer isn't anymore. doesnt even have access to a rep. he said there was corporate restructuring... i have a new email into the company.

Rick

Send some pictures of where the wires or cable terminates from the hub to the headlight Please. You may also want to post on the Electronics, Lighting, & Gadgets thread.

JeffOYB

Oh a Lighting group! that sounds good.

the wiring simply disappears into the headlight. i wish i could get in there...

Moe Zhoost

As a long time user of dyno hubs I have to say that occasionally lights quit working. For me, this has always been a wiring fault, usually at the hub connector, but sometimes there's a break elsewhere. It sounds like you made progress with diagnosing your issue (ruling out the hub, maybe). BTW, the setting on your multimeter needs to be something like 1-20 volts AC (not DC). The voltage will rise with increasing rpm.

The Breezer website lists the headlamp as a B&M Lumotech Lyt, which is a quality light. Is this the lamp that you have? Post some good pics of where the wires enter the light. The instructions for this light show spade terminals for both in (powering the headlamp) and out (to the tail light) so you should easily be able to check for current where the wires enter the lamp. Just pull the female spade connectors down far enough to show the metal of the male connectors and put your probes there. If you don't have current there, you have a break in your wiring somewhere. If you do have current and your light does not work, disconnect the tail light and try again. Still doesn't work, check that polarity is correct and try again.

Good luck

JeffOYB

i'll send pics later. it's not a sweet lumotec. it's something cheezy. and totally sealed up. we'll see.

fietsbob

I have had satisfactory performance from the German Schmidt dynamo hubs , https://nabendynamo.de/en/products/hub-dynamos/

if you want to just get a new wheel & go on with your riding, this dark season..

This one for my Brompton ..

JeffOYB

here is my light. I unmounted it and cant see any way inside.