E3020 Windscreen wipers/washers

Description

The windscreen wash/wipe system is operated by a lever on the right side of the steering wheel. The lever can be set to five positions that correspond to different functions by rotating it in a clockwise direction:

• windscreen wiper off (standstill);
• intermittent / automatic operation;
• continuous slow operation;
• continuous fast operation;
• 'antipanic' temporary fast operation (unstable position, turning the lever in an anti-clockwise direction).

Four different functions can be selected by rotating the ring nut in the intermittent / automatic operating position:

• on the 'BASIC' version the different intermittent speeds come on (from the slowest to the fastest;
• on the version with a rain sensor: the different sensor settings comes on: the activation of the rain sensor operates a windscreen wiper stroke as feed-back that the function has been switched on.

The adjustment of the windscreen wiper stroke frequency is automatic depending on the amount of water on the windscreen detected by the actual sensor: the frequency varies with continuity from nil (no stroke - windscreen dry) to wiping at the second continuous speed (heavy rain).

The windscreen wiper function is operated by pulling the lever toward the steering wheel: this action operates the washer pump: if the lever is held in position, the windscreen wiper also operates according to a specific control logic: the windscreen wiper is activated at the first speed: when the windcreen washer control ceases, an additional stroke is carried out.

The control of the functions described above is carried out by an electronic device inside the steering column switch unit which produces the intermittent function, controls the operation of the windscreen wiper motor and the electric windscreen washer pump and manages the rain sensor.

The windscreen wash/wipe circuit is protected by a specific fuse and is operated by the ignition-operated relay located in the underdashboard control unit.

The windscreen wiper and washer can be operated with the ignition key turned to MAR.(INT/A).

Description of operation

The electronic device inside the steering column switch unit H5 and the controls on the right lever are supplied at pin 11 of connector A by the line 'controlled by the ignition' (INT/A) of relay T12 protected by fuse F43, both housed in the underdashboard control unit B2.

Depending on the pre-selected function, the stalk unit H5 (connector A) sends control signals to the windscreen wiper motor N15:

• from pin 8 for fast operation;
• from pin 9 for slow and/or intermittent operation (for the intermittent operation the signal reaches the intermittent device and from there is sent to the control device and then to the motor);
• pin 6, on the other hand, receives the earth signal coming from the motor end of travel cam which stops operation. The windscreen wiper motor N15 is then connected to earth.

When operated, the windscreen washer switch on the steering column switch unit H5 sends two signals from pins 10 and 12 of connector A which directly operate the windscreen washer pump N20.

The rain sensor K85 is connected to the electronic device inside the steering column switch unit H5 at pin 4 of connector A from where it receives the supply, whilst it sends pin 2 of connector A the actual signal.

Wiring diagram

Components

Component location