Wiper and Washer Systems: Description and Operation

WIPERS AND WASHERS

All functions are initiated by means of a wiper/washer switch which is operated by the wiper lever on the right-hand side of the steering column.

Windshield Wiper
The windshield wiper system consists of the following parts:
- windshield wiper arms (2)
- windshield wiper motor on the air cowl trim panel
- windshield wiper linkage
- windshield wiper blades (2)
- wiper relay, in the central junction box (CJB)
- generic electronic module (GEM)
- wiper/washer switch, consisting of:
- wiper switch
- washer switch (pressure switch) and
- delay control switch (rotary switch, depending on model)

Windshield Wiper Functions
The windshield wiper motor has 2 speeds and a limit switch for the parked position. It is controlled by the wiper/washer switch on the steering column through the wiper relay and the GEM.

After switching the ignition to the ON position, the following 5 wiper functions are available:
- Off
- Once
- Slow
- Fast
- Intermittent

Wiper lever in the OFF position
If the wiper lever is switched from another position to OFF, the windshield wiper motor continues to operate at a slow speed until the parked position reached and then stops. This is effected by a second circuit via the limit switch. Power is thereby supplied to the windshield wiper motor after it is switched off until the limit switch cuts off the flow of current through the wiper relay (normally closed contact) and the wiper/washer switch to the windshield wiper motor.

Wiper lever in the ONCE position
Push the wiper lever downwards and release. It returns automatically to the OFF position. The windshield wiper motor performs one wipe cycle at a slow speed. The current flows through the wiper/washer switch to the windshield wiper motor.

Wiper lever in the SLOW position
Push the wiper lever 2 steps upwards. The windshield wiper motor operates at a slow speed. The current flows through the wiper/washer switch to the windshield wiper motor.







Wiper lever in the FAST position
Push the wiper lever 3 steps upwards. The windshield wiper motor operates at fast speed. The current flows through the wiper/washer switch to the windshield wiper motor.

Wiper lever in the INTERMITTENT position
Push the wiper lever 1 step upwards. The windshield wiper motor performs single wiping movements at a slow speed with pauses between them. Depending on the model, the wiping time interval is either set at the fixed setting of 9 seconds or 1 of 6 steps can be selected by turning the knob at the end of the wiper lever (position 1 = short interval, position 6 = long interval).

The wiper/washer switch sends a 12V signal to the GEM through the normally closed contact for the washer system switch that activates the wiper relay periodically, at 9 second intervals or according to the intermittent wipe time selected (depending on the model variant). The current flow to the windshield wiper motor is established through the wiper relay (normally open contact) and the wiper/washer switch.

Windshield Washer

WARNING: Washer fluid contains the poisonous substance methanol. Observe the safety rules. Failure to follow this instruction may result in personal injury.

The windshield washer consists of the following parts:
- windshield washer reservoir, below the front right-hand fender
- washer pump, on the outside of the washer reservoir
- 2 washer nozzles on the hood.

There are 2 possible functions, and these depend on how the wipers are operating:

Wiper lever in the OFF or INTERMITTENT position
The wiper and the washer pump operate for as long as the wiper lever is pulled towards the steering wheel. Releasing the wiper lever causes the washer pump to be switched off immediately. The windshield wipers perform 2 to 3 more cycles before they adopt the intermittent operation again (INTERMITTENT position) or stop in the parked position (OFF position).

Wiper lever in the SLOW or FAST position
The washer operates together with the wipers for as long as the wiper lever is pulled towards the steering wheel. The current flows from the wiper/washer switch through the washer pump to the GEM and the washer switch. The washer switch in the active state makes the ground connection.

Rear Window Wiper
The rear window wiper system consists of the following parts:
- rear window wiper motor
- rear window wiper arm
- rear window wiper blade
- rear window wiper relay
- one nozzle

Wipers and Rear Window Washer
To operate the wiper and rear window washer, push the wiper lever towards the instrument panel. The washer operates for as long as the lever is pushed. When it is released, it returns automatically to the rest position. The washer fluid for the rear window washer is taken from the same reservoir (see Windshield Washer) and also pumped by the washer pump.

The washer pump operates in the opposite direction of rotation for washing the windshield.

The current flows from the CJB through the washer switch to the washer pump. The washer switch in the active state makes the ground connection.