Motor vehicle rear window wiper system - has its operation controlled by control voltage power and/or mean value, supplied to input of regulator

In a combined windscreen and rear window wiper installation the latter is formed by a circuit with a control for the supply of the rear window wiper motor from a voltage source. The control has a control signal input, with the signal possibly dependent on the operation of the windscreen wiper portion. The operational mode of the rear window wiper portion depends on the strength and/or the instantaneous mean value of a control voltage supplied to the input (21) of the control (30). The control voltage can be directly tapped at a brush (12) of a permanent magnet motor (10) of the windscreen wiper portion. Pref. this motor has two brushes (12,13), running at a lower speed when the first brush (12) is energised, but at higher speed with the second brush (13) energised. The control voltage is directly tapped at the first brush.