Hello I am towing a heavy twin axle caravan to subtropical country soon so I decided to upgrade the cooling system of my E60. The tow bar was coded and is working fine I am curious if I need to do any more coding for the 600W fan to work, but the main issue I have is that the purchased fan (600W) has 4 wires (plus minus than red and yellow) and mine has only 3 (plus minus and signal - yellow with red stripe). The 4 wire plug is surprisingly cheap from BMW, but I have no idea where to run the wire to. Can anyone point me to the right direction? BMW stealer-ship is not helpful much just want me to drop the cat there and charge me £170 for running a wire and another £120 for coding that may not even be necessary. Anyone here with some expertise who can shine some light on it?

 

Your fan is computer controlled,so running a higher watt fan is useless. This fan has power, ground, and a pwm signal from the ecu that, gives all control to the fan when ever it needs it. If you plan on towing, transmission, and oil coolers will reduce the engines temperature.