My audi A6 2.4 Auto has a second fan behind the Rad. I used to hear this working and It would run when the car was turned off. I has the cab belt replaced some time ago, as well as a new gearbox and torque convertor. I have noticed that this fan no longer comes on. If I sit in heavy traffic both the oil temp and the water temp creap up. The oil goes to around 90-100 degrees. The water temp (normally at 90 dgrees) also goes up. The only way I have to cool things down is to switch the aircon to Econ and set the temp to high. I ran the car today for 3/4 hr at idle and the water and oil gauge did the same thing. I looked at the electric fan but it would not come on. I think that the fuse/relay fan motor or sensor must be at fault. But I don't know which fuse /relay to look at. How to test the fan. I also couldn't see a sensor in the rad. Basically my question is what is the most likley problem and how to I go about testing. The M25 is always jammed and the outside air temp is hitting 35 at the moment so sitting there with the heater on full blast I feer someting is going to melt (me or the car) any help out there?