How to Fix a Windscreen Wiper Motor in a Car

How to Fix a Windscreen Wiper Motor in a Car

Windscreen wipers ensure that your car’s windscreen is clear from any rain, dirt or snow. Immovable wipers can cause serious visibility problems for you while driving in bad weather conditions. Fixing a windscreen wiper motor is an easy task that mostly requires carbon brush replacement and thorough cleaning. But it is important that you know how exactly to take the motor apart. Read on to learn how to fix a windscreen wiper motor and get your wipers working by yourself.

Inspect the Wiper Motor Fuse

Before you can learn how to fix a windscreen wiper motor is it important that you check the motor’s fuse. Fuses play a critical role in ensuring that the excessive current does not flow to a component. You should make sure the fuse of the motor is not blown by testing it with a multimeter. Check and replace the fuse if it is damaged.

Disconnecting the Car Battery

The windscreen wiper motor is an electrical component that is powered by the car’s battery. In order to avoid any electrical accidents or damages, it is necessary to disconnect the battery as a safety measure.

You can also take this opportunity to check the battery. You can simply test the car’s battery to see if your car needs a battery replacement.

Removing the Wiper Motor

The windscreen wiper motor cannot be accessed directly as it resides in the motor gearbox present underneath a secured rack. Follow the following steps to remove the wiper motor from your car:

  • Before you can get access to the motor, you need to remove the wipers first. Using a wrench, unbolt the wipers from the point where they are attached.
  • Now unscrew the rack where the motor is present underneath the wipers.
  • You should now remove the rack from the car and spot the motor in the motor gearbox.
  • Follow the wires coming out of the motor and unplug the connector they are attached with.
  • Now remove the motor’s bulkhead by removing the bolts that are keeping it in place.
  • The motor is usually fitted with the pushrod system, taking the whole structure out of the car’s body.
  • Using a marker, mark the exact angles the rods are present in the pushrod system so that the rods can be placed in the same position and angle when putting them back inside.
  • Unbolt the pushrod system from the motor and disconnect the wiper linkages from the motor.

Need for a New Wiper Motor?

Inspect the wiper motor if it appears to be burnt out completely. Use a multimeter to check if it works fine. It is best to replace the motor if it is completely damaged. Take your old motor along while buying a new one so that you get the right fit.

You might also want to check your voltage regulator that could have caused the motor to burn out in the first place. If the voltage regulator is faulty, get a new one. Fit the new voltage regulator in the car before any other replacements or fixes.

Fixing the Old Wiper Motor

Test the motor using a multimeter, if your wiper motor appears to be fine then you can move on to fixing the wiper motor. Follow the following steps to fix a windscreen wiper motor:

  • Using a screwdriver, unscrew the long bolts on the endplate of the wiper motor.
  • The motor’s endplate is fiber locked; remove the plate and release the brushes from the spring locked holders by sliding the holder off the commutator present at the center.
  • Get new carbon brushes and replace the old worn-out brushes in the spring locked holders.
  • Ensure that the new carbon brushes slide smoothly.
  • Using sandpaper or filer, you can even smooth out any rough edges of the new carbon brushes.
  • Clean the main gear wheel of the motor, and the revolving part called the armature, using a cloth and methylated spirit. Make sure that the cloth you use is lint free so that no cloth fibers can stick with any of the motor components and cause any hindrance.
  • Inspect the commutator closely. If you notice any signs of rust or corrosion, use a rust converter to clean it.
  • Using emery cloth, wipe out any area that appears to be slightly burnt.
  • Next, you need to inspect the gear and see if its teeth are worn out. Replace it with a new spindle if it appears to be worn out.
  • Now you can resemble the motor. Do it in the same manner you took its components apart.

Fitting the Wiper Motor

  • Bolt the pushrod system to the motor.
  • Apply dielectric grease to the motor and bolt it back into the gearbox.
  • Adjust the linkages on the pushrod system to the marked points.
  • Plug the connector to the power supply. Before attaching the wipers back, turn on the motor at full blast from the switch to see if it is working. Now turn the switch off to ensure that the motor stops. This step is important as you want the wipers to start moving upwards from the downward position.
  • Now place the rack back and screw it into place.
  • Reattach the wipers in the exact same position you took them off.
  • Now throw some water on the screen and test the wipers. Check if the wipers need servicing. If their rubbers are completely worn out, you should consider replacing the wipers as well.

And there, you have fully functioning windscreen wipers through simple motor fixes.

Knowing how to fix a windscreen wiper motor can save you the hassle of going to the mechanic for a simple fix. Windscreen wipers and wiper motors are often overlooked in regular maintenance. A proper functioning wiper motor ensures that you have no difficulty viewing the road in rainy or snowy weather conditions. Thus, it is important to regularly replace its carbon brushes and gears that can wear out with time.

You also need to make sure that the wiring or electrical components of the wiper motor do not get damaged through an irregular current supply. Regularly check the electrical components of the entire car with an electric circuit testing tool to spot any damages or irregularities, which you can easily fix on your own.