27-08-2020, 09:09 AM
The dynamo should give about 8 volts if it is in good order. Test it by disconnecting the wires from the field and dynamo connections on the dynamo itself. Replace with two lengths of wire to each terminal on the dynamo, one to the D connection and the other to the F terminal. Link the free ends together and put the linked ends to one side of an analogue voltmeter (as Bob has said, a digital instrument will be affected by the electrical noise from the HT side of the ignition). Connect the other end to earth and start the engine. AS the engine is revved, the dynamo should start to show a voltage.
If it does and it rises to more than 8 volts, then the problem is going to be either in the wiring or in the cutout.
If it does and it rises to more than 8 volts, then the problem is going to be either in the wiring or in the cutout.