Dynamo Problem

[nhojw]

[]HELP!

I'm a novice re fitting a dynamo. I've just been fitting it - front light, rear light & dynamo. I had all items assembled on the bike and turned the pedals forward and heh presto, light emitting from front and rear!!

The problem is, I hadn't reassembled everything (eg. rear mudguard), as I hadn't wanted to do this until certain all worked. After tinkering around a little (i.e., slightly altering the placement of the dynamo, moving the wires to ensure they weren't in the way of the wheels etc.) I thought I'd perform a second demonstration to myself. However, when I turned the pedals the lights were not now emitting light! Big disappointment.

What could have gone wrong? I'm using a double cable on each light (front & rear). I didn't change any wires around whilst "tinkering". I'm using a B & M seculite plus rear light, a B & M Lumotec plus front light and a Nordlicht 2000 Dynamo.

Suggestions very much appreciated.

John

[JonHammond]

I commend your choice of twin cable.  I've always found relying on an earth return to be problematical.

Is it possible that you've got the wires the wrong way round on one or both lights?  Your return wires MUST follow the same electrical route as the earth equivalents, or a short-circuit will result.  Perhaps you didn't have a proper earth connection first time around (which is why twin cable is so much to be preferred), and then you got one when you moved stuff around.  This sort of cable normally has a line marking just one wire so that you can easily tell which is which at each end.