Spot on! Connected the grey plug, nothing happened, but then I noticed there was no bulb anywhere, so I put one in the socket and tadaaaam, there was light! Thanks!one feeds the trunk pop, one is for the tail lights if IIRC. I thought the black square at the bottom was a mercury switch to turn the trunk light on, but there should be wires going to it. See if the 2 wire grey harness will plug into the mercury switch