My aux fan wont shut off after the car is off, and I hear a clicking from under the hood as the fan turns off, on, then back off ect..... I think the fan relay is stuck or broken. Can anyone tell me where this is located? 1990 300E 3.0

My bad. The fan runs on high speed, only when the car is running. When I shut off the ignition, the fan turns off. The only time the fan is not running, is when I start it first thing in the morning, and the car is cold.

behind the fuse box..a few phillips screws hold the cover..

Ok thanks I got the cover off. There is a green one in front, then a silver, then a black, then two whites side by side. These are the square ones. There a two longer looking rectangular black ones. Do you know which one it is?

Sounds to me like you have a bad connecvtion at the temp sensor or a failing sensor..the relay would not click if it was stuck in the ON pospsiton

Yoy can tell which relay by unplugging it when the fan is on. Sould be the green one

I unplugged the black one, and the fan shuts off. I heard it clicking on and off, and the fan was turning on and off real fast. I guess I could try and replace the relay and see if it cures the problem. Where is the temp sensor located?

Swap that one woth the green one ..they are the same....