Ah, so current flowing through the diode = voltage drop. Got you!
Well rather than having each set of lights illuminated by each PIR sensor, I wanted the left one to turn on all the lights when a person enters and the right PIR sensor to turn all the lights on when the person exits. If it helps you understand a bit better, "Lamp 1" is the lights going through the garage and then "Lamp 2" is lighting going on the bottom rung of the fence to light up the garden and entry path. I lowered the wire to help me understand its the lower lighting...
There is probably going to be a PWM controller in there too on a side note.
Or is there a totally different way I should be doing this?