Mercedes-Benz W202 windscreen wiper mechanism faults
Mercedes-Benz W202 wiper stops partway across the glass or does not move although the motor runs. What is the cause?
The most common cause is the plastic gear in the mechanism having lost its teeth, or the nut on the motor shaft linkage having come loose. If the motor hums but the arm does not move, first check the nut and whether the linkage arm has come off.
How do I fix a worn gear or a loose nut on a Mercedes-Benz W202 wiper?
The nut is tightened back on and secured with thread locker. The worn gear is not available separately, but a metal replacement gear is available, or the whole motor can be replaced. The motor and mechanism come out as one unit from below the windscreen once the plastic covers are removed.
How do I lubricate a Mercedes-Benz W202 wiper arm linkage when it binds?
Stop the wiper at the upper corner so the arm is at its longest. Pull off the plastic cover at the lower end of the arm and lubricate the visible push rod with gun oil, CRC or silicone. Grease that is too thick does not suit the motor's angle gear, where a thin layer is enough.
How do I get the Mercedes-Benz W202 wipers to stop in the middle of the glass for service?
Switch the wipers on with the ignition off, then switch the ignition on and straight off again. The wiper stays in the middle of the glass. If the rest position is wrong, the arm is removed from the motor shaft and set to the correct position, since there are no marks.