Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, welcome to Just Answer. My name is***** problem is usually caused by a shorted blower motor control unit. The control unit is built into the blower motor. You will need to replace the blower motor to repair this problem. Also check for signs of water intrusion into the blower motor connector. Water can sometimes find it's way into the connector and short out the control unit.
Let me know if you have any questions.