1957 ES2 wiring

Hi

Two wires from the dynamo is correct if a wassel regulator is used you need to move the two feild wires internaly in the dynamo

this es2 mag / dynamo does not have an ignition switch

regards

Hi Charles.

There are two ways of wiring up a 2 brush dynamo. Lucas always used a 'shunt' setup but that doesnât mean to say someone hasnât changed it over the years. There is some more info on dynamo configurations here:http://www.themagnetoguys.co.uk/page1.php

Ignore the fact that there are 4 coils on the web page picture (I think we used a big Peugeot dynamo for the pictures), you have 1 wire coming out each end of the field coil and two brushes. If the dynamo hasn't been changed from itâs original âshuntâ configuration over the years then you should have one end of the field going to the F terminal, the other end of the field coil and one brush going to Earth, and the other brush going to the D terminal.

To check for output on a âshuntâ dynamo, join the D and F terminals together and connect one lead from your meter to that and the other end to earth (the body of the dynamo itself is your best bet so you donât run the risk of any poor earth connections elsewhere clouding the issue). Now if you run the engine you should get an output.

On a good dynamo we would expect 7-8 volts at around tick over and as you rev the engine a little you should get somewhere up around the 15 volts mark, bear in mind there is no load and no regulator in the system so the faster you rev it the higher the output. Don't hold it with the dynamo chucking out this sort of voltage for too long as it could do damage, but in the time it takes to rev it up and down a couple of times and check you have an output it will be fine.

If it doesnât give an output try flashing the dynamo, you need a little bit of residual magnetism in the field winding to get the dynamo to start up. If itâs been sat for a while this could have been lost. With the two terminals still connected together, take a wire from the non-earth side of the battery and touch it onto your two joined terminals - the earthed side of the battery on the body is already connected to the dynamo body of course. When you touch the battery wire onto the two joined terminals, youâll almost certainly get a little spark but thatâs nothing to worry about. Again, donât hold it there; just touch it on the terminals a couple of times. Then try running the dynamo again with the meter connected as explained above.

If youâre still not getting an output check that the commutator on the end of the armature is clean from oil and other dirt (also clean the end of the brushes off). If you still arenât getting anywhere it might need a new armature or field coil (or both!)

Iâve never used a Wassell regulator but they do come in positive and negative earth versions. From memory one version requires âseriesâ configuration, the other requires âshuntâ configuration - sorry, I canât remember which way round it is off hand. I know that when they first came out, there was some confusion caused by the positive earth ones being labelled negative and vice versaâ?â?.. We generally recommend AO Servicesâ voltage regulator, Al posts on here from time to time and you can find his details in the back of Roadholder as he is the clubâs electrical specialist. We have his regulators fitted to all our own bikes and they really are a fit and forget item that fits inside the old box.

If you get stuck or have any more questions our phone number and e-mail address is on the website I posted above.

Good luck

Andy