Bit late responding to your plea – sorry been away. Before anyone can help you need to supply rather more information. Most importantly what bike are you working on and whether it still has its standard electrics (6v dynamo for the earlier bikes and 12v alternator for the ETZs).
Secondly a bit more about the circumstances, has it suddenly failed or is a new to you bike you are trying to get running. Given a something to work with I am sure someone can help.