OK, Age is catching up with me.
When a Aqua Sig series 40 would come into the yard I used to figure out from the wattage rating of the individual bulbs (Anchor is 10w; Tri is 25w) whether my connections were right re Gnd, and which bulb should be lit when I applied the power to that bulb. Well it's not that easy when the incandesents are replaced with equiv Leds....simple resistance measurements don't work anymore...I think. Am I not seeing the forest for the trees?? What to do??
Are you trying to see why a fixture isn't working or are you trying to test a new installation? I'm a little confused.
If I am trying to figure out why something isn't working, I first test to see if I have power by using a separate bulb with a couple of wires soldered to it. If I have power, I clean the contacts and put a little dialectic grease on them. If it still doesn't work, I figure it's the bulb. I deal with led's pretty much the same way that I deal with incandesents except that the led's are polarity sensitive.
Some of the fixtures have a photo cell, but I don't think any of the replacement bulbs have them.