Mercedes-Benz W201 heater blower faults
Why does the Mercedes-Benz W201 heater blower not work at any speed?
Check fuse number 1 (red, 16 A) first. An oxidised fuse can look intact, so replace it with a new one. If the fuse is fine, the cause may be a worn ignition switch base or a broken resistor behind the battery.
Why does the blower squeal or whine in cold weather?
The blower motor bearings have dried out. You can clean them and regrease them with synthetic petroleum jelly, or replace the motor. Penetrating oil, for example CRC, dries out over time, so it is not suitable as a grease.
Why does the fuse blow immediately at high speed?
First make sure the fuse is the correct size. Dry bearings raise the motor current, so the motor should be cleaned and lubricated. A fault in the heater control panel can also blow the fuse.
How do you get to the blower motor?
Open the bonnet and remove the plastic covers in front of the windscreen, as well as the windscreen wiper mechanism and motor. After that the motor is held in place by three bolts. Replacing the blower takes about an hour.
Why does the new blower spin but the airflow is weak?
The blower may be spinning the wrong way. Swapping the positions of the wires reverses the direction of rotation. Also check that the impeller is the right-handed type.