After the engine is shut off, the heat from the engine soaks into the coolant in the block, as you have noticed most cars are up around 220 or more after sitting a bit, well the fan kit kicks on and cools the rad. down, and you can be sure the thermostat is open at 220 so the coolant will circulate the same way the overflow system works. I think this is the way it works, but to prove it does cool down the engine also, turn on the ignition after the fan shuts down, and there you have it. The water temp sensor is in the block, thus proving what has been cooled down.
The temp is usually down about 20 degrees. I really like the idea of getting rid of the terrible anount of heat build up in the car, for it is much more thant when driving it, at least for around 20 minuets or more.
Skip White