Jeff - what I was saying earlier is that most all of us on here get dirt and grease under our finger nails, so that thing on the little left side panel of a 169, and on the dash of the QL is the Hourmeter.
Art - the Hourmeter has it's own wire harness with a 3 connector plug. On the 169 the power is connected to the positive side of the coil (as Frank noted) and the ground is to the little screw holding the side cover to the frame - see my pic below.