Anyone added an electric radiator fan?

From the picture that you posted it looks like the one that I have. Here is my experiences with the electric fan. When I first bought the MH it overheated just looking at a hill. It actually melted the fan sensor at temp gauge sensors in the heads due to exhaust manifold leaks. After installing headers I hardwired the fan with a switch on the dash, thinking when I saw a hill coming I could start the fan at the bottom of the hill before a temp increase. From what I observed once the MH gets over 45 mph the fan has little affect on the eng temps. The fan helps at idle in hot weather with the AC on. The fan also helps to move air once you shut off the eng. The dash heater has more affect on reducing temps than the fan. Once the fan clutch kicks in you can very quickly see the temp gauge fall. So my conclusion is that it helps somewhat but if you are having overheating problems other things like headers, larger radiator( more rows larger dia tubes), new HD thermostat, air dams for front, free flowing exhaust etc would have a greater affect.