We removed the radiator fan last weekend. It's one of those direct drive units, so it always runs at the same speed as the motor. Dad believes it draws as much as 3 kW. In the world of e12 520i's, that is a big number! Off came the fan and in went an electric thermo fan. Lots of mucking around, especially with the assumption that the wire colours on the fan and relay would match up (they were from the same manufacturer after all), but no, black connected to blue and blue to black. How obvious!
Test runs seemed positive. I could feel a little more urge up above 5000 rpm, so could be useful at the next track day.
