scellpt

bmw e38 740, car is now overheating sometimes and sometimes its fine, first all is fine then i gas the AC because was not cold enough, all is still fine then one day put on AC but when its time 4 the Auxillary fan to come on to cool the condenser it doesnt so engine starts 2 overheat, but now without the AC on the engine is still overheating and the fan does not come on at all , so i ran a direct hot wire 2 the fan to check if it works and it does and the coolant is fine, Also there is an ORANGE 40AMP FUSE in the engine compartment next to 2 pink ABS RELAYS and i BLUE RELAY that has no ID on it, that 40AMP FUSE KEEPS BLOWING everytime i change it but it doesnt blow straight away, when i go out and come back home i check it and its gone anyone know what that 40 AMP FUSE IS FOR,and why it could be blowing.