For a alternater with a higher output use a second wire of the same size from the second large terminal. 14 mai 2017 ยท I'm rewiring the 3 pin lucas alternator. Going by diagrams on line,I have the + and - larger wires from the alternator running to the solenoid.The smaller yellow brown wire,running from alternator to a warning light,then to the ignition switch,and from there, back to the same point on the solenoid.