When I turn off the engine, radiator blower stays on forever and never stop

This is an electric fan that is turned on by a temerature sensor and relay. It is an eleven year old car so the relay or sensor is most likely not working. The right answer is to replace them. The cheap and dirty answer is find the wire that is powering the fan and put a switch on it so you can shut it off and on. Run it up to under the dash somewhere. Use a larger wire than the one you are cutting into because of the distance to the dash. This would destroy your resale value but get you through till the old car finally dies.