If I drive up to a conductor and the VoltWitch has no lighted display can I assume the line is dead and apply grounds?
No, the VoltWitch is designed and intended to be a way to stay in a vehicle and drive a line. ALWAYS use a voltage detector approved by your company to test the line prior to ANY operations including grounding. DO NOT depend on the VoltWitch as your only verification that a line is energized or not energized. ALWAYS verify the condition of the line with a voltage detector approved by your company prior to any operations such as grounding.