I was working in a pub (full of dole type psseads drinking in the middle of the afternoon), door contact was high res but I had an idea it was more than one door in series with a jb somewhere, this was before the days of EOL. Meter on the panel attached to the door contact cable, I went to prop a fire door open, when I came back meter was gone, nobody saw a thing. Ironically I nearly got my old meter out when I opened the back of the van, but I thought nah I would rather use my nice one.