.. Anybody any knowledge on the wiring setup for the cooling fan on 2001 Golf 
TDI. The fan fails to come on sometimes and the engine is overheating. 
There's a switch on the rad, but it must switch a control unit or ECU. If I 
disconnect the rad switch the fan comes on after about a minute, so 
something is monitoring this circuit. However, It will sometimes switch off 
again and the engine will still overheat.
Anyone any experience of this system.

John