How to Replace a Wiper Motor

In this article, you will learn how to diagnose, remove and install a faulty windshield wiper motor. It is important to have the right tools, so check to be sure you have the things you need. One of the most important things you'll need is the same make and model wiper motor as the one you are replacing.

Things You'll Need

• Heavy-duty diagnostic test light
• Standard metric wrench and socket set
• New or junkyard wiper motor
• Magnetic or plastic tray to hold all the removed nuts and bolts
• Pick to remove the various plastic body components that cover mounting screws
• Flathead screwdriver
• Phillips head screwdriver
• Pair of needle nosed pliers

Instructions

1. Find the wiper motor. The wiper motor will be either on the driver's side or passenger's side of the vehicle on the firewall or bulkhead of your vehicle. Car manufacturers mount the wiper motor on different places on the firewall, but it is always a round blackish cylinder that you can carry in one hand. It will be under or near one of the wiper blades under the grate.

2. Access the wiper motor. Remove the wiper arms by taking your flathead screwdriver and removing the rubber stoppers on both wiper arms to gain access to the mounting nuts. Remove nuts with a socket wrench using a 13 mm socket. Once nuts are off, you may have to use a little force to wiggle the wiper arms back and forth or side to side to lift and remove them from the tapered metal screw splines that hold them together firmly.

3. Remove the screening filter grate. It is the metal (or plastic or fiberglass) filter that prevents debris like snow or dirt from clogging the HVAC intake vents. Do this by using the pick tool to remove the plastic cover pins that cover the screws that hold the grating in place. Use a Phillips or flathead screwdriver to remove the grating. You should now have access to the wiper motor and should be able to see it clearly.

4. Remove the wiper motor from the bulkhead. Unplug the connectors leading to the wiper motor. Use the 10 mm socket to remove the upper bolt holding the wiper motor onto the bulkhead. The upper bolt holding the wiper motor may also be holding the solenoid pack. If so, remove the solenoid pack from the upper bolt to clear it out of the way.
   Next, remove the lower mounting bolt in the same way. If there is another upper bolt, remove that. If there is another lower bolt, loosen and remove it too. The other lower bolt is often a little more difficult to reach so assemble a swivel extension from your socket toolbox to get to it. The number of mounting bolts on a wiper motor vary from 2 to 5 depending on the make and model of your vehicle. You will need to wiggle and jiggle the wiper motor out of its place from the bulkhead after you've removed all the bolts.

5. Diagnose the wiper motor. Unplug the connector going to the wiper motor to test whether there is power going through the plug. Connect the test light to the ground side (the negative post) of the battery. Turn the key on and turn the wipers on to any of the wiper selections.

6. Touch the plug connection marked with your selection with the test light to see if you're getting any power to that function. If the probe lights, you're getting power to that function. Do the same thing with the wipers turned on intermittent and low to test each function in turn.
   If each function of the wipers is receiving power, you should next test to find out if the wiper motor is grounded to the firewall. To do this, switch your light probe clamp from the negative post of the car battery to the positive post. Then stick the probe into the wiper motor case. If the probe lights, then you know that the ground side of the circuit is good.
   If one of the functions of the wiper motor is faulty, you will need to replace it with a new wiper motor or a used one from a car junkyard. If you choose to buy a used one from a junkyard, be sure to get one from the same make and model year of your vehicle. If by accident you get a different one, it won't work in your vehicle.

7. Install your wiper motor. Make sure that you have all bolts sticking through the rubber mounting sleeves on the wiper motor before attempting to install the motor. The reason for the rubber is to dampen and quiet the vibration these motors create when turned on.
   Insert the wiper motor in the same place as the old one by lining up the bolts to the holes and hand tightening each bolt on the motor first. Do not tighten down the bolts until you are sure that the bolts are all properly aligned into their holes.
   Once you have started each of the mounting bolts and are sure they are aligned, take your 1/4 inch socket wrench and the 10 mm socket and tighten each bolt down. Remember that if your solenoid pack was held to the firewall by any mounting bolts and washers, you must reattach the pack to the bolt and washers before you tighten anything down.
   Finally, you need to reattach the wiper arms and the grate that you removed to get at the wiper motor.

Tips & Warnings

• Tightening down all the wiper motor bolts not holding down any other parts of the vehicle before reattaching the other parts with the remaining wiper motor mounting bolts will make your work a little easier.

• Make sure you know where the negative post of your battery is located before clamping on the light power probe.