Joined: Nov 2006
Posts: 19,810
Likes: 597
From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Oh, man, two dynamos! I've never seen that before. I wonder why there's an extra one on the back-- maybe the frame doesn't conduct well enough for the conventional one-wire system? I'd try to make it work with one dynamo (lose the rear one) but... whatever.
The dynamos are probably fine. If the light doesn't work most likely the problem is in the wiring, or the bulbs.