How To Repair A Windshield Wiper Motor

Removing a windscreen wiper motor

On pushrod systems, you can commonly lift out the motor and linkage together. Disconnect the wiper artillery and unplug the electrical connections, then remove the bolts holding the motor to the bulkhead.

Disconnect the battery . Remove the electric connections from the motor , preferably labelling them so that you lot can refit them to the right terminals .

With a rack -and-wheelbox system, disconnect the rack from the motor gearbox and unbolt the motor.

With a pushrod system, it is usual to take out the motor and linkage in one piece. Ofttimes they are mounted together on a plate that tin can exist unbolted and removed.

Before removing a pushrod arrangement, mark the angles of the rods to aid refitting. On some cars, the motor and linkage are mounted together on a plate to simplify removal from the motorcar in one slice.

On some cars you unbolt the pushrod at the motor spindle , remove the bolts that hold the motor and lift it out on its own.

Before removing the motor and linkage, free the wiper spindles by removing the arms and unscrewing the spindle nuts. Note the position of whatsoever spacers and washers.

Mark the linkage to show how its parts are angled when the blades are in the park position.

If the motor failed when the wipers were not parked, mark the positions of the blades on the windscreen as well equally the angles on the linkage, as a guide when refitting.

With the machinery removed, disconnect the linkage from the motor.

Fixing the motor

A wound-field motor

Undo the long bolts holding the endplate to the motor casing. Remove a fibre lock plate to free the leap loaded brush holder.

Two types of Lucas wiper motor are in general apply on English cars. Other motors are very similar, but you may not be able to get new brushes or other parts for them. If you lot cannot go parts, buy and fit a new motor.

The before (wound-field) Lucas motor is square. Take out the long bolts securing the endplate.

Pull the fibre lock plate free from the brushes, open the jaws of the spring-loaded brush holder and slide it off the commutator .

Await at the brushes - if they are worn downward to well-nigh ; in. (3 mm), fit new ones, making sure these slide freely. Employ a fine file to remove whatever roughness.

Accept out the armature and main gear wheel, and clean them with methylated spirit on a lint-free cloth.

Fitting new brushes

On a foursquare motor, open up the jaws of the bound-loaded brush holder to slide it off the commutator.

If the commutator is slightly burned or corroded, clean it with fine emery fabric; if withal, information technology is desperately pitted or scored, fit a new or substitution motor.

If the gear teeth are worn, fit a new gear spindle.

Reassemble the motor, packing the gearbox with plenty of high melting-signal grease.

A permanent-magnet motor

Marker the position of the motor casing against the gearbox so yous tin refit it the same fashion, and so undo the casing securing bolts.

The casing of the later ( permanent-magnet ) Lucas motor is circular. Before you unbolt the casing mark its position on the gearbox. If you replace it the incorrect way round, the motor will tum backwards. There may be more 2 brushes if the motor has more than ane speed. Inspect the brushes, and if they are worn to in. (three mm), fit new brushes and holders. Remove and clean the armature and main gear wheel with methylated spirit on a lint-complimentary cloth. The gear has a dished washer under it; refit information technology the right way round. Clean the commutator with fine emery material.

If you have to fit a new gear, purchase a replacement with the aforementioned sweep angle, which is marked on the bicycle -110 degrees, for case.

Wiring the brushes back

On a round motor, tie the brushes back into their holders with a fuse wire while you refit the commutator.

When you reassemble the motor, the brushes have to be pressed dorsum into their holders while you fit the commutator.

Tie them back with 4 in. (100 mm) lengths of 5 amp fuse wire. Twist the ends and let them stick out.

Push in the commutator until it just enters the space between the brushes, and so sideslip off the wires and slide the commutator dwelling house.

On some makes of motor, brushes are soldered into place. Solder one brush at a fourth dimension.

Cut off the sometime lead, carefully noting its route, and match it with the new one. Melt a little solder on a new lead and the contact point, then solder on the lead.

Do non let solder run along the pb and stiffen it.

Some motors take exterior screws for adjusting armature end float (that is, lengthwise complimentary play), which should be only partial. Other motors have springs to have up cease float.

Refitting the motor

When reassembling a pushrod linkage, employ the guide marks you made to position rods at the correct angles.

Some wiper motors accept a knurled nut for adjusting the parking position.

In one case the motor is back in place, test the wipers with the blades lifted off the screen. So wet the screen with the washer and test with the blades in the wiping position.

On sure wiper motors, turning the domed switch comprehend above the gearbox adjusts the parking position.

Source: https://www.howacarworks.com/accessories/fixing-a-windscreen-wiper-motor

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