Edlux II front light stopped working?

[Dave B]

Hi, on my Thorn Nomad II I have a SON dynamo hub powering just a front light Edlux II. It’s suddenly stopped working after many years of use . Checked the connectors but still no light! Is it the light , or is it the hub? Is  there anyway of findings out the cause of the fault?

[steve216c]

From experience of a family full of bikes on various hub dynamos and the good news is that it is probably the cheapest component that has failed, namely the cable.

But obviously you need to check to be sure. And this can be done without fancy equipment in most cases.

First check your dynamo is working. You will need a low voltage lightbulb. Although your hub probably puts out 6v you may be able to test this with a lower volt torch lightbulb e.g at 3v or a car light bulb at 12v. I have an old EverReady 3v battery bike lamp (batteries removed)from the early 90s to which I’ve attached a couple of garden tie wires to the copper connectors in the lamp fittings and put the lamp in on position so the circuit will light when voltage is applied. Connect or hold the other 2 ends to the Dynamo output connection at the hub. Spin the wheel lightly and if bulb lights you know hub is good.

To test the lamp you need to pass voltage into it. Although the dynamo is 6v you can test this with less voltage. If you have a powerbank for a USB device and an old usb cable you don’t mind killing you can chop the non powerbank end off (while not connected to anything!)and expose the individual inner cables. You‘ll need to strip back 2 of potentially 4 cables which are carrying the power. I will see if I can find my cable and upload as example of which 2 colour cables mine was. Presumably this is standard but I only ever chopped one cable so cannot compare.
Some LED lamps are not fussy which is positive or negative from power source. Others are a bit more fussy and only take power one way around. If you apply power and nothing happens then try again reversing cables connected. If lamp lights, then all is good.

At this point you know if either hub or lamp are toast. And hopefully you have proved both are working so you just need to replace the cable between both hub and lamp.

As mentioned at opening, cable fatigue is most likely culprit. So without all the testing you could just try a new length of cable and seeing if that works. It doesn’t have to be bike specific cable. Old speaker cable or even a length of electric flex. would work to test at very least. One of my bikes has rear dynamo light wired with loudspeaker cable for over 5 years and still working.

[Dave B]

Thanks for that most comprehensive advice , I will have play and see if I can find the fault.

[PH]

Good reply from Steve, I haven't got a lot to add other than that all my dynamo failures have been related to the connectors - when I say all, that's just three in thirty years!  Are you using the spade version of the light, or the more recent jack plug connector?  I've had the spade type fail when the cable has broken off the spade, probably fatigue, but might be worth removing the heat shrink to have a proper look.   I've also had the female part of the jack plug fail, no reason I can see, just stopped working, rather annoying as there's no repair, wipes out any advantage it has.
I've never had an issue with my Edelux lights, but know someone who had a problem with the switch,  though it might have been that they couldn't turn it off - it needed the black ring/switch replacing, though they discovered this by testing it with a magnet.

[steve216c]

Here's example photos of what I used to test hub and lamp if working.

Using good old Everready bike lamp without batteries but with garden wire on the terminals. Would work with an old torch or even wires held by hand against the terminals of bulb if you can hold steadily:



For using a power bank to power lights when old bottle dynamo failed, I cut old USB cable to expose the cables. In my case I added spade connectors to make it easier to join to existing dynamo circuit. But for testing purposes, exposed wires would work. It looks like it was red and black were the power carrying cable colours in my case. But I have no idea if this is standard cable colouring convention, so if you have more than 2 cables making your own such USB conversion, then take care to check if you have a 4 core wire especially if colours are different to mine.



and finally, it doesn't have to be dynamo cable... at least for a short term fix. But good quality dynamo cable ought to have more flexible/less brittle internal wires. BUT I have had success in using cuts from this old speaker cable which are still going strong years later. Mine is a bit thicker than typical dynamo cable, but otherwise works a treat. No promises an guarantees for old cable other members might have laying around, but who knows, perhaps you have something that performs better than bike shop dynamo specific cable in your odds and ends drawer of offcuts?

[Dave B]

Thanks again for the advice, i have the spade type. I am correct in thinking that the wiring from the Edlux II lamp is “hardwired” into the lamps?

[PH]

Thanks again for the advice, i have the spade type. I am correct in thinking that the wiring from the Edlux II lamp is “hardwired” into the lamps?

It is, though I've read there are ways into it.  It's co-axial cable, so pretty tough, far more so than the more common bell wire type.  If there's a breakage, it's likely you'll be able to feel it by running it through tour fingers. 
How old is it?  All SON products have a five year warranty.

[steve216c]

I don't know how UK distribution deal with Schmidt/SON repairs outside of guarantee. In Germany forums suggest they will often repair/replace even outside of guarantee period as a gesture of goodwill.
I don't have an. edelux but found this link with some pictures of one taken apart if you decide to take a peek. https://swhs.home.xs4all.nl/fiets/tests/verlichting/koplampen/Schmidt_edelux/analyse/index_en.html

[Dave B]

Thanks for that Steve. I gaining access to another SON hub tomorrow and will attempt to run  the light off that. Have emailed Thorn ref warranty , but strongly suspect I have passed the five year mark. Will resist the temptation to take a peek, I have poor track record on such matters. Thanks again for your advice

[Dave B]

The SON hub on my Nomad II is the problem.

Attached a 9v Duracell battery direct to the spade connectors and the Edlux II lit fine.

Attached the Edlux II to another SON Hub and again it worked fine. 

Attached another bulb  to My Nomad II SON and no light, did the same to the other SON hub and the bulb lit .

The good news is that hub is in warranty!

[steve216c]

Glad you could figure it out. And great that the dynamo is still under guarantee too. I hope that the repair/ replacement doesn’t take too long. I ride 24/7 all year round with lights on knowing as a car driver how easy it is to overlook a cyclist even in daylight. On the couple of occasions I have had light problems, even in daylight and neon jacket I have felt far more vulnerable till I can get home and fix the problems.

Good luck sorting it all out.

[Dave B]

SON dynamo update. Ten days ago  Schimdt repaired and returned my hub via SJS - it looks like new.  With the parts purchased from SJS my LBS have built it into a nice new wheel . It’s great to have a light back on running day & night , It felt odd not to. Even the salmon kool stop pads are working great on my new none css rims.

[steve216c]

... It’s great to have a light back on running day & night , It felt odd not to...

I know that feeling. Being a cyclist who also drives cars occasionally, I know how easy it is to overlook cyclists even in daylight. And on the rare occasions I have not been able to ride with lights on I literally feel naked and exposed. Same deal if I forget my helmet. (don't worry- I promise NOT to ride naked and exposed to see if it really does feel the same )

With the improvements gained with LED lamps and hub dynamos (even my humble non-SON dynamos) I just leave my lights permanently on day and night. Car drivers are more aware of me than of non lit bikes during daylight hours. IMHO it is a good habit to make your presence known when out on your bike. MOST car drivers are not interested in a collision and are probably grateful for the cyclists they can see well ahead on the road during the daylight hours than those who lurk between the shadows without lights.

I don't really notice the extra drag when riding even though it probably costs me 3% more leg power to run dynamo all day. Hub dynamos are the best upgrade I can recommend to almost any cyclist with far more pros than cons over battery lights.

[CanAmSteve]

Just wanted to add a bit of data here - I recently started using a bike that had been stored for a year. It has a Edelux II lamp and a SON hub dynamo, but the lamp was not working. I noted some found the magnetic switch was the issue, so I thought perhaps it had stuck in "off". I used a small but powerful neodymium magnet instead of the switch ring (which has a tiny magnet) and that seems to have re-awakened the internal switch. No working normally. Possible a good long bumpy ride would have had the same effect, but I thought the info might be useful to others

[Jornw]

Hi,
My trusty "Edelux" headlight mounted on my Raven Tour became increasingly weak, and stopped working during a very wet bicycle tour in Norway. Back home in my garage the next week I opened the lamp and found some moisture inside. I found that the O-ring sealing the front glass had deteriorated and become brittle. This was clearly a potential leak path. I dried the interior of the lamp carefully using a heat gun, and E-mailed SON for advise. They were very responsive, and mailed me a new O-ring the following week free of charge. Impressive. I have professional experience in technology related to pressure sealing, gasket materials and -compatibility. Unfortunately, I do not know the material of the O-ring, but cheap rubber can be anticipated. My theory is that the O-ring had deteriorated due to a either long term water exposure (less likely) or chemical incompatibility with a chemical applied on bike by previous owner.  In the car business, such chemicals are marketed as spray-on "fluid polishing wax". I assume that such "polishing" of the bike is probably a bad idea considering that other gaskets may be damaged.
The Edelux headlight worked like new once dried and re-assembled. I also applied some silicone compound around the cable entry into the lamp housing, for improved water tightness.