To install a charge wire to a voltmeter/ammeter sngle wire alternator (assuming it is a 12SI alternator, 2 wires, 1 an2 2, on the side connector area of the alternator), connect a single wire, 14 gauge will work, to the number 1 terminal on the alternator, and run it to one side of the indicator light. The other side of the light to an ignition switched to "on", 12 volt feed, new light is a charge indicator light, just like stock.