Thanks for quick reply Tommy - first light has 2 black wires and one white. I assume one of the black wires and the white wire go on to the second light. Also assume power from the switch, as you said, goes into the first light via black and white wires. The photocells have only a black wire going in and a black wire going out.
Thanks - believe this is the model:http://www.homedepot.com/p/Hampton-Bay-Photocell-Replacement-PHOTOCELL/202022460#.UdryCtuulhQRegarding the white wire in the second light, does not appear anything has been broken off, there is only one white wire coming from behind the wall into the light fixture.
Yes - but I have since the initial wiring (which looked just like your diagram) I have taken off the photocell from the second light. Seems to me that if the power goes off or on to the first light it should also control the second light? But obviously you are the expert, not me. I can re-wire it to reattach the photocell to the second light, but in view of your thought that these fail quickly and easily, maybe I should go with a different type. Is there one you recommend which has a smaller footprint, that will control both lights with one hookup?