Jixxer06

2000 a6Q 4.2L 95K

I have read plenty of threads like about aux fan not working, but none are like this problem.

My secondary aux. fan is not coming on. I have replace the CTS and the thermal switch, all the relays are good. No fuses popped, also checked the 40amp under dash checked positions 20 and 21 (the fold relay panel) new FCU. the fan works i have direct connected it and it also comes on with the a/c and heater. Am i missing something? I think maybe the wire connecting to the sensor is bad. Is there a way i can unplug the housing from the thermal switch and try and jump the prongs in the housing to see if the fan comes on..?...if so how do i do it and what are the wire color codes? any help or advice is thanked. thanks for helping out!

Jixxer06

Well i continued searching and i read that i could be in the early stages of my water pump going out.

At low speeds or idle the cars is fine. from what i found out its cause the pump has a plastic impeller and at higer rpm or speeds basicly anything over idle the impeller slips and dosen't move enough coolant to keep the car cool. but it moves enough to keep it from over heating. which means as the water pump wears out it will move less coolant.


what do you guys think.?...how can i check the water pump? I heard that some have a leak hole of them and if they start to leak it could mean its going bad. TIA