OK `let me start from the beginnign. My da bought his car about 4months ago and after two weeks the lower radiator hose blew off. It still had the factory clamp on it. But my dad not knowing drove the car home and it got so hot it cut off. I fixed bled the system and he was fine. A few weeks later his guage quit workin in the dash no big deal. Flash foward i got his car from the body shop went to my local auto part store and put a new sensor in for the guage. The car is going pegging the gauge and a code p1641 is coming up the fans will not come on unless i turn on the a/c or disconnect the the switch at the pump. I also had my car next to his and swapped my relays to his car no change. I did a search and i saw a thread about changing the harness which. would the harness be bad even if the fans were still coming on. I also changed the sensor on his water pump.