Been tackling this AC problem for ever and have read and reread post. I have replaced the blower fan, amp, heater servo and yesterday the Aux Water Pump. I discovered my old aux pump was frozen after connecting it to a 12v bought a new one connected it and still nothing. I then decided to connect it to a 12v and boom car started blowing hot air. So I know the new one works but for some reason the car isn't communicating with it? It connects to the fan wire harness and the item circle in the picture. What is hat called? Is this the culprit?