Wipers and washers (Description): Description and operation

Description

General

All markets have a common wiper system with headlamp powerwash as an option.

The wipers system comprises two front wipers and one rear wiper which are powered by electric motors. A washer reservoir is located in the front left hand wheel arch and is fitted with two electric pumps. Each pump supplies washer fluid to either the front or rear screens. On certain models, a third pump can be fitted to operate a headlamp power wash function. Operation of the front and rear wipers and washers is controlled by the driver using switches located on a steering column stalk and push button switches on the fascia.

Control of the wipers and washers is achieved by the following components: l BCU. l IDM. l Front wiper relay. l Front wash/ wipe switch. l Variable delay switch. l Front wiper motor assembly. l Front washer pump motor. l Rear wiper relay. l Rear wiper switch. l Rear washer switch. l Rear wiper motor. l Rear washer pump motor.

Both the Body Control Unit (BCU) and the Intelligent Driver Module (IDM) control the wiper system. The BCU controls the time delay function of the wiper system and is located below and behind the passenger glovebox. During engine cranking the BCU prevents wiper functions. Two relays are located in the passenger compartment fusebox. The relays control the delay operation of the front and rear wipers. The relays are an integral part of the fusebox and cannot be renewed separately.

Power for the wiper system is supplied by the IDM, which is integral with the passenger fusebox and cannot be renewed as a component. A serial communication link allows communication between the IDM and the BCU.

The system has diagnostic capabilities through TestBook.

Front wipers

The two front windscreen wipers are operated by a linkage assembly and an electric motor located under the plenum grill below the windscreen. The linkage and motor assembly is handed for left and right hand drive vehicles. The motor is an integral part of the linkage and cannot be replaced separately.

The linkage comprises a pressed steel mounting plate which provides for the attachment of a wheel box at each end. The mounting plate is secured to the bulkhead with flanged nuts which attach to a stud plate located behind the bulkhead. A link arm is attached to each wheel box by a short link and secured with circlips. The link arm has an attachment hole centrally located along its length for the electric motor drive link.

The electric motor is mounted in a recess in the bulkhead below a sealed cover plate. The drive spindle of the motor protrudes through the cover plate and is fitted with a link. The link is attached to a tapered spline on the motor spindle and is secured with a lock washer and nut. The opposite end of the link is attached to the central attachment point on the link arm and secured with a circlip.

Each wheel box has a taper splined shaft which allows for the attachment of the wiper arm which is secured with a washer and nut. The shaft of each wheel box is passed through a rubber sealed aperture in the plenum. The wiper arm attachment to the splined shaft has a pivot to which the remainder of the arm is attached. The two parts of the arm are connected by a spring which controls the pressure of the blade on the screen to a predetermined amount.