NOTE!! the yellow wire coming out of the reg/rec never has it's own power,, it just "T's" into the yellow wire that comes from the engine's stator wire, that then goes to the headlight dimmer switch. it takes excess voltage and delivers it back to ground. thus the regulator part of the regulator/rectifier. S1070 @ SUB-W-4 (S1258)THIS sub harness can be used for 6 V or 12 V so you must use a bulb that matches your regulator rectifier. This harness and your 6 or 12v regulator rectifier will only keep the ac current regulated to the headlight (and or tail light) so they don't burn out.. SUB-W-4 (S1258) @ 12V_or_6V CT70 REGULATOR RECTIFIER_PIGTAIL CLICK FOR_INSTRUCTIONS (SUB_W_12/12/6/6) (S1255)YOU CAN USE A 12V REG/REC & BATTERY WITH THIS COMBINATION (MUST CHANGE ALL LIGHTS).... OR USE THE 6V REG/REC AND USE THE STOCK BATTERY AND LIGHTS....PIC SHOWS 12V... BUT JUST LEAVE THE STOCK BATTERY IN FOR 6 VOLT NOTE!! the yellow wire coming out of the reg/rec never has it's own power,, it just "T's" into the yellow wire that comes from the engine's stator wire, that then goes to the headlight dimmer switch. it takes excess voltage and delivers it back to ground. thus the regulator part of the regulator/rectifier. SUB-W-12/12/6/6 (S1255) @ CT70_ENGINE_SWAP CONVERTING_TO 12_VOLT CT70K1_TO_1982 WIRING_KITYOU MAY NEED 3 OR 4 DASH BULBS. YOU WILL PROBABLY ALLREADY HAVE THE 12 VOLT REGULATOR/RECTIFIER AS MOST NEW ENGINES INCLUDE THEM. IF YOU HAVE BLINKERS YOU WILL NEED FOUR OF THOSE BULBS TOO.