I see # 2 Aux fan sensor, and three #3 Coolant temp. sensor. Aren't these the same thing? I thought the coolant temp. sensor, sends a signal to the relay to turn on the high fan. What does # 2 aux fan sensor do then? My high speed fan wont shut off, and I cant figure if its the relay or the coolant temp sensor. Now what is # 2 supposed to do?