on the driver's side below rear of headlight on air conditioning lines close to rad is a two pole sensor (can't remember the color) the two wires coming from the sensor go to a plug. Unplug the connection - if the fan stops your sensor may be bad or you have a pressure problem in air conditioning. My 560 has reverse problem. I have to short the wires together to get the fan to come on. It is in winter storage now but will take up the troubleshooting this spring when it warms up (-35F today).