3239315 - E3020 WINDSCREEN WASH/WIPE - Functional description

Functional description

The windscreen wiper control on the steering column switch unit H5 selects the various operating modes of the windscreen wash/wipe. The stalk unit H5 is supplied at pin 3 of connector D from the ignition-operated line (INT/A) of the relay R1 protected by the fuse F14: both are contained in the junction unit B1 .

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

• from pin 2 for continuous fast operation: the signal reaches the motor directly;
• from pins 3, 4 for continuous slow and medium-fast oeration: the signal arrives from the intermittent device and is then sent to the motor
• from pin 5 for intermittent operation: the signal reaches the intermittent device and is then sent to the motor; this signal differs according to adjustment ring position, which adds no resistance, one resistance or two resistances to the line to obain the three different intermittence speeds.

The windscreen wiper motor N15 is then connected to earth. It consists of the actual geared motor, the end of travel contacts and the electronic adjustment and control device. When operated, the windscreen washer switch on the steering column switch unit H5 sends two signals from pin 8 and pin 9 of connector A, which reach the pump for operating the windscreen washer N20 directly. One of the two signals (pin 6 of connector A of H5 ) is also sent to the electronic device inside the windscreen wiper motor N15 which manages the operation of the windscreen wiper coupled with the windscreen washer. The same signal is also sent as a go ahead to allow the operation of the headlamp washers (  See E3022  HEADLAMP WASHER ).