The wiper system changed completely when the car switched from positive to negative earth in November 1967 (GAN4-60460 / HAN9-72041). All wiper components, motor, rack, wheel boxes, arms, and blades, differ between the two systems and are not interchangeable. The correct system must be identified by chassis number before ordering any wiper component.
Positive-Earth Wiper System (DR3A)
The positive-earth system uses a square-body Lucas DR3A wiper motor with a flexible rack operating two wheel boxes mounted through the scuttle panel. The motor mounts to a bracket in the scuttle area. The rack tubing, wheel boxes, bezels, and spacers are all specific to this system. Wiper arms are spoon fitting only, available in standard and polished finishes.
The wheel box seals (ferrules) prevent water entering the scuttle from around the wiper spindles, perished ferrules are a common and easily overlooked source of water ingress and should be renewed if any dampness is found in the scuttle area.
Negative-Earth Wiper System (14W)
The negative-earth system uses a round-body Lucas 14W motor with a different rack and wheel box arrangement. Two wiper blade fitting styles were used during the 14W system's production: spoon fitting was used from the changeover through to GAN5-123750, and straight fitting was introduced from GAN5-123751 onward through GAN6 to the end of production. The blade fitting must be matched to the arm, spoon fitting blades will not lock onto straight fitting arms and vice versa.
Wiper Arms and Blades
Wiper arms and blades are available in standard black, polished stainless, and (for straight fitting) black finish options. Arms and blades should be replaced together to ensure optimum spring tension against the windscreen, a tired arm spring allows the blade to lift at speed, reducing the wiped area. The motor retainer strap is available in standard and stainless steel, the latter being a worthwhile upgrade on cars where the original has corroded.
Washer Bottles and Pumps
Three washer bottle and pump arrangements were used across production: one for vertical-flow radiator cars (to GAN4-66225 / HAN9-77590), a second for crossflow 1275cc cars (GAN4-66226 onward through GAN5), and a third for the 1500 (GAN6) with its own bottle, strap, and mounting arrangement. Each uses a manual plunger pump delivering fluid through tubing to chrome or black plastic jets on the scuttle. The bottle, bracket, pump, tubing, T-piece, and jets are all specific to the radiator and chassis specification.
Electric Washer Conversion
An electric washer pump conversion kit replaces the manual pump with an electrically driven unit, providing more consistent and reliable wash delivery at the press of a switch rather than requiring a hand to leave the steering wheel to operate the manual pump. The electric conversion is available for both positive and negative earth systems.
Smartscreen Intermittent Wipe
The Smartscreen intermittent wipe conversion provides timed delay wiping, a feature not available on the original specification. The conversion is available for both positive and negative earth systems and fits within the existing wiper circuit without modification to the motor or switch. A combined Smartscreen wash/wipe version is also available for negative earth cars, integrating the intermittent wipe function with an electric washer pump in a single installation.