The Germans like to use what is called a final stage unit to control electric motors in certain applications such as auxiliary fans and blower fans. It is a potted device that uses semi-conductors and integrated circuits to control the speed of the fan. It is almost always located on the fan assembly itself and usually requires replacement of the entire fan assembly as they often do not sell them as a separate unit. I hope this is helpful to you and if you need more specific data, then I will request our resident MBZ expert to assist you. Dr. Hagerty ♥

Answered by Dr. Hagerty (expert)
9,720 answers provided

Dr. Hagerty is correct on the integration of the control unit into the fan assembly. To disconnect the fan so you can stop it:
1. open the hood of the vehicle and stand at the front of the car.
2. Look at the fan assembly lower right hand side (your right hand)
3. You should see a single electrical connector to the fan assembly. Disconnect this connector and the fan will stop.

Answered by gfimotorcars (expert)
691 answers provided