Trying to fix up my 80s Triumph bike which has a Sturmey Archer 3 speed dynamo hub. The hub has two screws which connect to two cables. I think the hub generates an AC supply and powers a front and rear light.

Here are some photos:


So the things I'd like to achieve are, to:

1) identify the bulb so I can purchase two new ones

  • think i may have found them! My lamp says 6 volts, 0.1 amps which i worked out as 6 volts and 0.6 Watts, maybe this one will work??.

2) be able to run an AC supply though the circuit to see if it works at all

3) see if the dynohub can generate an AC supply

  • Would a multimeter help?

4) to find the name of the small metal plates that connect the wires to the screws on the Sturmey Archer hub

  • I think they might be called hook connectors but not sure how to wire them up

Any help would be much appreciated. I've fallen at the first hurdle and cant even identify the bulbs!


1 Answer 1


Basic troubleshooting steps

1) Is there power coming from the dynohub? Use a multimeter on AC 6V (possibly 20Volt setting required on a standard meter)

2) Is the power capable of flowing to the lamps? Use a meter on continuity-beep or on resistance setting to check.

3) Does the lamp fitting carry power to the lamp? Same as #2

4) Does the lamp work? Use continuity or resistance test again.

Replacing the wire is a good idea if it looks manky, and new lamp holders will give you more light for the same input. The hub is the most expensive part.

  • thanks very much for your help. Will all basic multimeters have the function you mention or will i need to try and find a special one?
    – James
    Commented Mar 24, 2016 at 13:04
  • 1
    @james any normal multimeter will have resistance and an AC voltage setting to suit. You could make a continuity-only tester using a battery, wires, and a suitable DC lightbulb to test connectivity of wires... a torch/flashlight and wires can be used for this in a pinch.
    – Criggie
    Commented Mar 24, 2016 at 22:54

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