Cookster,don't no if you mean the purple wire going to the switch side of the starter solenoid marked (s) or if you have (HEI)the pink wire that runs to the (BATTERY +) from ignition switch to Distributor Cap.Should also be a purple/White wire that comes frome Ignition Switch to (Neutral Safty Switch) or (Clutch Switch)what ever the case may be.The Pink and Purple wire should light your test light with (KEY) in the on position,and have no power with Key OFF.