L322 Range Rover System Description and Operation
WIPERS AND WASHERS
DESCRIPTION AND OPERATION
84-9
Wiper Motor
The motor assembly comprises a dc motor which drives a gear wheel via a worm drive attached to the motor spindle.
The gear wheel has a central spigot which provides the attachment point for the motor crank.
The motor is connected electrically by a four pin connector. The connector supplies two battery voltage feeds to the
motor. The motor has three sets of brushes with one brush connected to ground. One feed is direct to the motor brush
opposite the ground brush and operates the motor at normal (slow) speed. The second feed is connected to a motor
brush which is offset from the ground brush and operates the motor at fast speed. With the power supplied through
this brush, the current flows through fewer coil windings. This results in a lower resistance to the current flow to the
ground brush and gives a higher motor rotational speed.
Output control of the wiper motor is through a double contact relay. The relay is located in the engine compartment,
adjacent to the transfer box ECU, behind the battery. The relay is a tan colour for identification.
The motor has an internal track which signals the BCU when the wipers have reached the park position. The park
signal is an open circuit when the wipers are in the park position. When the wipers are switched off and the BCU
receives the park position signal from the motor, the BCU shorts the motor via a relay bridge circuit. This short circuit
has the effect of applying a brake to the motor, giving precise positioning of the wiper blades in the park position.
Wiper Arms
1 Blade locking clip
2 Wiper arm collet
3 Wiper arm
4 Spindle cap
5 Self locking nut
6 Wiper angle adjust shim
7 Wiper angle adjuster
8 Wiper blade
9 Air deflector