Dynamo system problems

[julian]

I have B&M Lumotec front and rear running off a Nordlicht 2000. Has always worked well but suddenly only the standlight comes on (faintly) when the front wheel stops turning. I don't know if it's the main bulb or a wirinf fault or some other problem. Does anyone have any ideas?

[Dave Whittle Thorn Workshop]

Sounds like a bad earth, is the dynamo double wired orare you getting the earth back through the frame? Also are you running front only (with a 3w bulb) or a rear as well (2.4w bulb)?

[drossall]

Had a similar problem with the same set-up. Drives me nuts. Fitting a new bulb worked for a bit but then the same again.

In my case it was the bulb not making contact with the centre copper tab in the light. I bent the latter forward and hey presto! Seems like the standlight only comes on if there is no current - ie the bike's not moving - which seems fair enough. However, obviously current is reaching the light or it would not charge the standlight.

Recently the whole thing just fell to bits. In fairness I damaged it a bit opening it once, but I don't think the lighting reliability is my fault. I am looking for a better standlight.

[luceberg]

Try putting a dab of Vaseline on all the connection points. It's brilliant at stopping corrosion.

[drossall]

Don't think it was corrosion. I think the contact bends so that it does not touch.