Mercedes-Benz S-class W140 - Repair manual and operation

14.3. Check of the electric motor of a screen wiper

The electric motor of a screen wiper is in a water-collecting compartment under a windshield. For check it is necessary to remove the corresponding cover.

Designation of plugs

On the electric motor there are following plugs:

The plug 31 is accession of weight (the general for all electric equipment of the car).

The plug 53 receives tension for the first speed of a screen wiper.

The plug 53a feeds with current (+) the extreme provision of a screen wiper. The electric motor receives through a brush tension until the cleaner does not return to a starting position when the driver switches off a screen wiper.

The plug 53b gives tension for the second speed of a screen wiper (an auxiliary winding).

Via the plug 53e the electric motor is stopped at return after shutdown that the screen wiper did not pass the parking through the situation.

Are available not always: the plug 53 with gives food to the windscreen washer pump.

Check of the electric motor

At first it is necessary to find out what has defect, the electric motor or is absent food. At the same time it is necessary to work as follows:

1. Rasstykuyte the multicontact socket at the electric motor.
2. Bring 2 auxiliary cables (+) and (-) from the rechargeable battery of the car to the screen wiper electric motor:
   Carry out one cable from the positive plug of the battery to the plug 53 or 53b.
   Bring the second cable from the negative plug of the rechargeable battery to the plug of 31 electric motors.

3. Now the electric motor has to turn on depending on the used plug on I or II steps. If it does not occur, the electric motor or the corresponding step have defect. Remove the electric motor.