[farqhuar]

Hi, got an interesting problem which I have been having for a while.

My '06 987 is in great shape - only covered 100k kms - but occasionally overheats running around town as the radiator fans never turn on no matter how hot the engine gets.

The way I try to avoid this is to put the AC on, which gets the fans spinning.

So basically I know the fans are good (and I assume the wiring too) but what I can't work out is what sends the signal to the fans to get them to operate?

The temp gauge arrow sits vertically during normal running and it is only when I stop at the lights and notice a pool of fluid running out near my right rear wheel that I know I have a problem.

I am assuming the temp sensor must be sending out the correct signals if my gauge is working ok. I tried shorting out the temp sensor wires (to simulate a hot fluid situation) but the radiator fans still won't operate.

In addition, whenever I start my car after it has been sitting for ten minutes after switching it off, the engine compartment fan will run continuously for around 15 minutes of driving. My understanding is that the 987 radiator fans should continue operating when the engine is shut down, and the fluid is above a certain temperature, in order to cool the hot engine down to a set temp.

Any thoughts or suggestions on where I can start the diagnostic process will be much appreciated.