@Michael McKelvey, Fear not! I did the same thing with my cooler fan switch - it's watching the output side of the cooler. I assumed (without much input from the SOC back then) that I didn't really want the fan coming on if the unassisted cooler was handling things, so my fan comes on when the cooler output creeps over 180 and needs additional help. I figured thats a big margin (20 degrees) to where I wanted it at 200 and it seems to be nicely managing oil temp on days from 70 up to mid/upper 90's out (I don't drive much over that).
MOnitoring the heat output side is a carry-over from my computer days. We didn't give much of a rat's pitutie for the input temp to the card cage (it was usually 55F coming in) but we sure as heck wanted to know if the output started to climb over 90F and would start to take automatic action.