Connect one wire to the switch and the other wire to the plus side of the battery or other unswitched 12VDC source (actually this is the last connection to make!!!). I taped the switch to a cross bar. The switch allows me to turn the light off if I want to leave the frunk open. Remove the wires on the frunk light (spade connectors pull off). The open side of the switch connects to a spade connector on the light. The other side of the light connects to any convenient ground.