Land Rover Discovery: Windshield Wiper Motor and Linkage Assembly - Description

Windshield Wiper Motor

NOTE:

Right Hand Drive (RHD) wiper assembly shown

1. Electrical connector
2. Electric windshield wiper motor

The windshield wiper motor comprises a 12V electric motor and gear wheel and worm drive, contained in an integral housing.

The windshield wiper motor drives an integral 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 windshield wiper motor and linkage assembly are a single component and cannot be replaced separately.

The motor assembly is connected to the vehicle harness by a four pin electrical connector. The electrical connector provides two battery voltage feeds from a fast/slow wiper relay in the Battery Junction Box (BJB), a wiper park feed from the Central Junction Box (CJB), and a ground path for the motor assembly.

The wiper motor is prevented from operating when the hood is open. If the vehicle speed is more than 3 km/h (1.9 mph) the CJB considers the hood closed and the wiper motor will operate.

The motor contains a park switch which is connected to the CJB. When the motor is switched off, the CJB detects the park switch opening and stops the windshield wiper motor in the park position.

If the windshield wipers or the linkage become obstructed, the CJB will remove power to the windscreen wiper motor if the park signal does not change state within 6 seconds. The wiper motor will remain disabled until the obstruction is cleared or an alternative active wiper mode is selected.

Three disable events are allowed until a 180 second disable period is activated or until the next ignition cycle when the event counter will be reset to zero.

Windshield Wiper Linkage

NOTE:

Right Hand Drive (RHD) wiper assembly shown

1. Pivot crank
2. Main tube
3. Pivot crank
4. Motor assembly
5. Pivot - left windshield wiper arm
6. Rubber mounting (3 off)
7. Link rod
8. Link rod
9. Pivot - right windshield wiper arm
10. Motor crank
11. Rubber mounting

The windshield wiper motor and linkage assembly differs between Left Hand Drive (LHD) and Right Hand Drive (RHD) models. The wiper linkage and motor assembly are not available as separate service components.

The windshield wiper motor and linkage assembly is attached to the vehicle body with screws and washers at each end. The screws are located in rubber bushes in the wiper linkage assembly which isolate the assembly from the vehicle body. A rubber mounting is located behind the motor and engages on a spigot on the vehicle body to locate the linkage assembly.

The windshield wiper motor and linkage assembly comprises a main tube with a pivot housing assembly located at each end. The motor assembly is attached to the tube by two screws. The motor output shaft is fitted with a crank. A link rod is connected to the motor crank and is connected at the opposite end to one of the pivots via a crank. The connection changes with the drive hand of the vehicle. The driven pivot crank is fitted with a second link rod which is connected directly to the crank on the opposite pivot assembly

The motor crank converts rotary motion from the motor output shaft into linear movement of the link rods. The cranks connected to each pivot, convert the linear motion of the link rods back to rotary motion of the pivots. This rotary motion is passed to the wiper arms and blades causing the blades to wipe a reciprocating arc across the windshield.

Each wiper arm is located on a taper spline on the respective pivot. A nut is screwed on the end of the pivot shaft and positively secures the wiper arm on the taper spline.

The wiper blades are attached to the wiper arms with quick release fittings.

The wiper arms are spring loaded to maintain a constant wiper blade pressure on the windshield. The wiper blades are of the conventional blade type with the wiper blade supported on two pivoting yokes which apply an even pressure along the length of the wiper blade and allow the wiper blade to curve and match the windshield profile throughout their arc.

Wipers and WashersRear Window Wiper and Motor - Description

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