Sorry for the late response, I was out all day. Okay, when you open the hood and look down on the engine, these sensors are located about an inch to the right of the valve cover (between the valve cover and air filter housing) & screwed into the block itself. The sensors are located in sequence starting at the end of the block near the oil filter and comes towards the fan. The aux fan sensor is the third one located next the air filter housing. If pull the wire from the sensor, you will notice that it has two prongs with a blue base. Hope this helps. I will try to attach a picture of the sensor and post it again.