Hi guys my BMW E60 520 (2.2) recently overheated, causing headgasket to fail. I have had all the work carried out, head skim and pressure test., new water pump, temp sensors, thermostat. It's now overheating again and I think the fan is at fault. As I can not hear it working. Before I spend crazy money on a new electric fan how do I test it's working. The fan has three wires one black,red (thick) and a thin wire? The fan is off the car currently.
Any help would be great,