Powerdynamo brings new ignition & light
to your vintage motorcycle



Technical Help



You report on: "No or very dimm lights, but engine is running!"

Please first check whether the regulator delivers voltage. For this, disconnect the red and the brown cable from the regulator. Than connect to the regulator brown (6v regulator: white) and red some headlight bulb and start the engine. 
  • If the bulb shines you have to look for the problem in the bikes wiring. Notably
    # the wire that goes to the main switch or the main switch itself might be damaged
    # you might have a ground connection problem
  • If the bulb stays dark, you seem to have a problem either with the regulator or the stator coil.
    # Disconnect the two black wires that run from the stator to the regulator ...
    # ... and measure the AC voltage at these black cables with engine running. Do not rev the engine too high, this may blow your bulb

    In a 12 volt system should be about revolutions/100 in volts. That is 1000 revs give abvout 10V, 5000 revs 50 volts. If this is so, the stator is ok and probably the regulator is defective. 
    Take a sniff at the regulator, if it smells burned - it is damaged (mostly caused by a wrong wiring)!
  • If there is no voltage at the black generator cables, you have probably a faulty stator. 
    # first carefully inspect the stator for any damage of the copper coils 
    # take the stator off and check whether one of the wires are pinched (see more info here)
    # check resistance of the stator coils (in the case of lighting broblems between the 2 blacks)
       ADVICE: it may be that a cheap meter will not show the "0.xxx Ohm".
  • It happens that actually everything with the production of lighting voltage is OK, but still lights are very dim. The culprit here often is a faulty battery which burns the offered voltage. To check, just disconnect the battery for a test and check how lighting is (with running engine). If lights are ok than, your battery needs to be replaced. More info see here.